Move systemd-measure to its own source subdirectory

We have other subdirectories with just a single C file. And I expect
that systemd-measure will only grow over time, adding new functionality.
It's nicer to give its own subdirectory to maintain consistent structure.

meson.build

@@ -2382,6 +2382,7 @@ subdir('src/locale')
 subdir('src/login')
 subdir('src/machine')
 subdir('src/machine-id-setup')
+subdir('src/measure')
 subdir('src/mountfsd')
 subdir('src/modules-load')
 subdir('src/mount')

src/boot/meson.build

@@ -1,16 +1,6 @@
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
 executables += [
-        libexec_template + {
-                'name' : 'systemd-measure',
-                'conditions' : [
-                        'HAVE_BLKID',
-                        'HAVE_OPENSSL',
-                        'HAVE_TPM2',
-                ],
-                'sources' : files('measure.c'),
-                'dependencies' : libopenssl,
-        },
         libexec_template + {
                 'name' : 'systemd-sbsign',
                 'conditions' : [

src/measure/meson.build

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+executables += [
+        libexec_template + {
+                'name' : 'systemd-measure',
+                'conditions' : [
+                        'HAVE_BLKID',
+                        'HAVE_OPENSSL',
+                        'HAVE_TPM2',
+                ],
+                'sources' : files('measure.c'),
+                'dependencies' : libopenssl,
+        },
+]