osdict: Drop usb-tablet checking

Historically over time it's been more likely that an issue is reported
for osinfo-db missing the usb-tablet annotation. So for example we
always enable it for the default 'generic' case. We also want to
enable it for osinfo's 'unknown' case too.

Rather than add another check for that, let's just drop the osinfo
checking entirely. Some very old OS don't support usb-tablet, but
specifying it for those cases doesn't cause issues AFAIK, and users
can override it with `--input none` if they want.

Signed-off-by: Cole Robinson <crobinso@redhat.com>

tests/data/cli/compare/virt-install-kvm-rhel5.xml

@@ -56,6 +56,7 @@
     <channel type="spicevmc">
       <target type="virtio" name="com.redhat.spice.0"/>
     </channel>
+    <input type="tablet" bus="usb"/>
     <graphics type="spice" port="-1" tlsPort="-1" autoport="yes">
       <image compression="off"/>
     </graphics>
@@ -123,6 +124,7 @@
     <channel type="spicevmc">
       <target type="virtio" name="com.redhat.spice.0"/>
     </channel>
+    <input type="tablet" bus="usb"/>
     <graphics type="spice" port="-1" tlsPort="-1" autoport="yes">
       <image compression="off"/>
     </graphics>

tests/data/cli/compare/virt-install-openbsd-defaults.xml

@@ -54,6 +54,7 @@
     <channel type="spicevmc">
       <target type="virtio" name="com.redhat.spice.0"/>
     </channel>
+    <input type="tablet" bus="usb"/>
     <graphics type="spice" port="-1" tlsPort="-1" autoport="yes">
       <image compression="off"/>
     </graphics>

virtinst/guest.py

@@ -804,7 +804,7 @@ class Guest(XMLBuilder):
         usb_tablet = False
         usb_keyboard = False
         if self.os.is_x86() and not self.os.is_xenpv():
-            usb_tablet = self.osinfo.supports_usbtablet()
+            usb_tablet = True
         if (self.os.is_arm_machvirt() or
             self.os.is_riscv_virt() or
             self.os.is_pseries()):

virtinst/osdict.py

@@ -372,14 +372,6 @@ class _OsVariant(object):
     def supported_netmodels(self):
         return self._device_filter(cls="net")
 
-    def supports_usbtablet(self, extra_devs=None):
-        # If no OS specified, still default to tablet
-        if self.is_generic():
-            return True
-
-        devids = ["http://usb.org/usb/80ee/0021"]
-        return bool(self._device_filter(devids=devids, extra_devs=extra_devs))
-
     def supports_virtiodisk(self, extra_devs=None):
         # virtio-block and virtio1.0-block
         devids = ["http://pcisig.com/pci/1af4/1001",