drm/i915: drop all drmP.h includes

Needs just a few additional includes here and there.

Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190108082709.3748-1-jani.nikula@intel.com

drivers/gpu/drm/i915/intel_mocs.h

@@ -49,7 +49,6 @@
  * context handling keep the MOCS in step.
  */
 
-#include <drm/drmP.h>
 #include "i915_drv.h"
 
 int intel_rcs_context_init_mocs(struct i915_request *rq);