gralloc: Remove localized hw specific pixel format

Reduces need to build with drm_gralloc headers elsewhere in tree.
Returning to system/graphics.h approach.

Change-Id: I26717cfe0a9a83ab263c26803e2849eb55560696
Depends-Change-Id: I405398b172fab19949fef33c89a60132b1bd0ea9
Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com>
diff --git a/gralloc_drm.h b/gralloc_drm.h
index 8554cf7..dcc6a66 100644
--- a/gralloc_drm.h
+++ b/gralloc_drm.h
@@ -25,7 +25,7 @@
 #define _GRALLOC_DRM_H_
 
 #include <hardware/gralloc.h>
-#include "gralloc_drm_formats.h"
+#include <system/graphics.h>
 
 #ifdef __cplusplus
 extern "C" {