selinux: Add CM-specific file_contexts

Change-Id: Ie70c59acedbb7be2f5b34a83c1d3d011f440ba05
diff --git a/sepolicy/sepolicy.mk b/sepolicy/sepolicy.mk
index 94df225..af929d9 100644
--- a/sepolicy/sepolicy.mk
+++ b/sepolicy/sepolicy.mk
@@ -7,5 +7,6 @@
     vendor/cm/sepolicy
 
 BOARD_SEPOLICY_UNION += \
+    file_contexts \
     seapp_contexts \
     mac_permissions.xml