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_audio.c

@@ -27,7 +27,6 @@
 #include <drm/intel_lpe_audio.h>
 #include "intel_drv.h"
 
-#include <drm/drmP.h>
 #include <drm/drm_edid.h>
 #include "i915_drv.h"