sepolicy: enable wakeup_sources debugfs for system_app

for wakelocks

Change-Id: I49b19231db6e5fe74c5c94bb9006e67049f90741
diff --git a/sepolicy/system_app.te b/sepolicy/system_app.te
index a142f29..798477d 100644
--- a/sepolicy/system_app.te
+++ b/sepolicy/system_app.te
@@ -9,5 +9,5 @@
 #allow system_app sysfs_ksm:file rw_file_perms;
 
 # Read /sys/kernel/debug/wakeup_sources.
-#allow system_app debugfs:file r_file_perms;
+allow system_app debugsfs_wakelock:file r_file_perms;