cm: Allow LiveDisplay to write to color_enhance

The proper permissions for the color_enhance sysfs node weren't
being set, rendering the color enhancement switch useless.

Set the proper permissions for LiveDisplay to toggle color enhancement.

Change-Id: Ic8dba8953b73a497cb01a645834c0e7934092b38
diff --git a/sepolicy/file_contexts b/sepolicy/file_contexts
index 8cea018..0a54e3a 100644
--- a/sepolicy/file_contexts
+++ b/sepolicy/file_contexts
@@ -47,6 +47,7 @@
 /sys/devices/virtual/graphics/fb0/cabc          u:object_r:livedisplay_sysfs:s0
 /sys/devices/virtual/graphics/fb0/rgb           u:object_r:livedisplay_sysfs:s0
 /sys/devices/virtual/graphics/fb0/sre           u:object_r:livedisplay_sysfs:s0
+/sys/devices/virtual/graphics/fb0/color_enhance u:object_r:livedisplay_sysfs:s0
 
 # fsck
 /system/bin/fsck\.ntfs                          u:object_r:fsck_exec:s0