Add labeling for crosvm+arm64 rtc

Updated a comment for the pnp rtc which is x86-only, and added the
platform device rtc emulated on arm64 only.

Bug: 143531490
Change-Id: Ie9f59c4cbbf5a419b81966936b18aa7da9d756e9
diff --git a/shared/sepolicy/vendor/genfs_contexts b/shared/sepolicy/vendor/genfs_contexts
index dc586f5..fa48056e 100644
--- a/shared/sepolicy/vendor/genfs_contexts
+++ b/shared/sepolicy/vendor/genfs_contexts
@@ -1,5 +1,6 @@
 genfscon sysfs /bus/iio/devices u:object_r:sysfs_iio_devices:s0
-genfscon sysfs /devices/pnp0/00:00/rtc  u:object_r:sysfs_rtc:s0 # qemu virtual rtc
+genfscon sysfs /devices/pnp0/00:00/rtc  u:object_r:sysfs_rtc:s0 # qemu x86 virtual rtc
+genfscon sysfs /devices/platform/2000.rtc/rtc  u:object_r:sysfs_rtc:s0 # crosvm arm64 virtual rtc
 genfscon sysfs /devices/platform/rtc-test.0/rtc/rtc0/hctosys u:object_r:sysfs_rtc:s0
 genfscon sysfs /devices/platform/rtc-test.1/rtc/rtc1/hctosys u:object_r:sysfs_rtc:s0
 genfscon sysfs /devices/platform/rtc-test.2/rtc/rtc2/hctosys u:object_r:sysfs_rtc:s0