hwdb: drop quotes from XKB_FIXED_*= properties

The properties are not unquoted by udev, so the quotes effectively became part
of the value.

Even though those properties were added quite a while ago
(086c001e29a86287d7b639cb71d1fc6408920c53,
d7d31692bf7cde5dce7f4ed3cae429a5b302a9f0), they never started being used
(because of issues with having multiple layouts), see
https://gitlab.gnome.org/GNOME/mutter/-/issues/906,
https://bugzilla.gnome.org/show_bug.cgi?id=775681.

Let's remove the quotes while we still can.

From https://bugzilla.gnome.org/show_bug.cgi?id=775681#c7:
> Note to self: the values for XKB_FIXED_LAYOUT and XKB_FIXED_VARIANT are
> quoted, meaning that we need to remove the quotes before passing the values
> from udev_device_get_property_value() to xkb_keymap_new_from_names()
> otherwise the compilation of the keymap fails (please don't ask how I found
> out...)

hwdb.d/60-keyboard.hwdb

@@ -72,14 +72,14 @@
 
 # A device with a fixed keyboard layout that must not be changed by
 # the desktop environment may specify that layout as:
-#   XKB_FIXED_LAYOUT="us"
-#   XKB_FIXED_VARIANT=""
+#   XKB_FIXED_LAYOUT=us
+#   XKB_FIXED_VARIANT=
 # Examples of such devices: the Yubikey or other key-code generating
 # devices.
 
 # A device where the scan code to key code mapping is insufficient and
 # requires a special key code to symbol configuration may specify that with:
-#   XKB_FIXED_MODEL="xkbmodel"
+#   XKB_FIXED_MODEL=xkbmodel
 # Examples of such devices: Chromebooks where the top row is used for both
 # media and F1-F10 keys.
 
@@ -1796,8 +1796,8 @@ evdev:input:b0003v1050p0111:*
 evdev:input:b0003v1050p0116:*
 # OKE Electron Company USB barcode reader
 evdev:input:b0003v05FEp1010:*
- XKB_FIXED_LAYOUT="us"
- XKB_FIXED_VARIANT=""
+ XKB_FIXED_LAYOUT=us
+ XKB_FIXED_VARIANT=
 
 ######################### LACK OF MODIFIER LEDS ############################
 # This section lists keyboard which do not have their own LEDs for some
@@ -1846,4 +1846,4 @@ evdev:atkbd:dmi:bvn*:bvr*:bd*:svnLENOVO:pn*:pvrThinkPadX1Carbon3rd:*
 # Chromebooks
 evdev:atkbd:dmi:bvn*:bvr*:bd*:svnHewlett-Packard*:pnFalco:*
 evdev:atkbd:dmi:bvn*:bvr*:bd*:svnAcer*:pnPeppy:*
- XKB_FIXED_MODEL="chromebook"
+ XKB_FIXED_MODEL=chromebook

hwdb.d/parse_hwdb.py

@@ -32,7 +32,7 @@ try:
     from pyparsing import (Word, White, Literal, ParserElement, Regex, LineEnd,
                            OneOrMore, Combine, Or, Optional, Suppress, Group,
                            nums, alphanums, printables,
-                           stringEnd, pythonStyleComment, QuotedString,
+                           stringEnd, pythonStyleComment,
                            ParseBaseException)
 except ImportError:
     print('pyparsing is not available')
@@ -54,7 +54,6 @@ EOL = LineEnd().suppress()
 EMPTYLINE = LineEnd()
 COMMENTLINE = pythonStyleComment + EOL
 INTEGER = Word(nums)
-STRING =  QuotedString('"')
 REAL = Combine((INTEGER + Optional('.' + Optional(INTEGER))) ^ ('.' + INTEGER))
 SIGNED_REAL = Combine(Optional(Word('-+')) + REAL)
 UDEV_TAG = Word(string.ascii_uppercase, alphanums + '_')
@@ -94,7 +93,8 @@ def hwdb_grammar():
     matchline = (matchline_typed | matchline_general) + EOL
 
     propertyline = (White(' ', exact=1).suppress() +
-                    Combine(UDEV_TAG - '=' - Word(alphanums + '_=:@*.!-;, "') - Optional(pythonStyleComment)) +
+                    Combine(UDEV_TAG - '=' - Optional(Word(alphanums + '_=:@*.!-;, "'))
+                            - Optional(pythonStyleComment)) +
                     EOL)
     propertycomment = White(' ', exact=1) + pythonStyleComment + EOL
 
@@ -114,6 +114,7 @@ def property_grammar():
     dpi_setting = (Optional('*')('DEFAULT') + INTEGER('DPI') + Suppress('@') + INTEGER('HZ'))('SETTINGS*')
     mount_matrix_row = SIGNED_REAL + ',' + SIGNED_REAL + ',' + SIGNED_REAL
     mount_matrix = (mount_matrix_row + ';' + mount_matrix_row + ';' + mount_matrix_row)('MOUNT_MATRIX')
+    xkb_setting = Optional(Word(alphanums + '+-/@._'))
 
     props = (('MOUSE_DPI', Group(OneOrMore(dpi_setting))),
              ('MOUSE_WHEEL_CLICK_ANGLE', INTEGER),
@@ -138,9 +139,9 @@ def property_grammar():
              ('POINTINGSTICK_CONST_ACCEL', REAL),
              ('ID_INPUT_JOYSTICK_INTEGRATION', Or(('internal', 'external'))),
              ('ID_INPUT_TOUCHPAD_INTEGRATION', Or(('internal', 'external'))),
-             ('XKB_FIXED_LAYOUT', STRING),
-             ('XKB_FIXED_VARIANT', STRING),
-             ('XKB_FIXED_MODEL', STRING),
+             ('XKB_FIXED_LAYOUT', xkb_setting),
+             ('XKB_FIXED_VARIANT', xkb_setting),
+             ('XKB_FIXED_MODEL', xkb_setting),
              ('KEYBOARD_LED_NUMLOCK', Literal('0')),
              ('KEYBOARD_LED_CAPSLOCK', Literal('0')),
              ('ACCEL_MOUNT_MATRIX', mount_matrix),