hikey/hikey960: Add userland support for dmabuf heap dev dir

This patch adds the userland bits to support the dmabuf heap
dev dir (/dev/dma_heap/*).

Change-Id: Id837c19adc931973e9791355b06bd0aceff60275
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/sepolicy/file_contexts b/sepolicy/file_contexts
index 5c010f0..0fb634c 100644
--- a/sepolicy/file_contexts
+++ b/sepolicy/file_contexts
@@ -13,7 +13,7 @@
 /dev/hifi_misc         u:object_r:audio_device:s0
 /dev/hi_vdec	       u:object_r:video_device:s0
 /dev/hi_venc	       u:object_r:video_device:s0
-
+/dev/dma_heap(/.*)? u:object_r:graphics_device:s0
 /dev/graphics/fb0      u:object_r:graphics_device:s0
 
 # files in /vendor