omap: include omap_drm.h independently

omap_drm.h uses data type defined in stdint.h, but that header was
not included.

omap_drm.h includes drm.h as a local file when it is part of the
compiler c flags.

This two issues are fixed. New code can include omap_drm.h alone.

Signed-off-by: Víctor Manuel Jáquez Leal <vjaquez@igalia.com>
Signed-off-by: Rob Clark <rob@ti.com>
diff --git a/omap/omap_drm.h b/omap/omap_drm.h
index f677cd8..9c6c0e4 100644
--- a/omap/omap_drm.h
+++ b/omap/omap_drm.h
@@ -29,7 +29,8 @@
 #ifndef __OMAP_DRM_H__
 #define __OMAP_DRM_H__
 
-#include "drm.h"
+#include <stdint.h>
+#include <drm.h>
 
 /* Please note that modifications to all structs defined here are
  * subject to backwards-compatibility constraints.