drm/vc4: fix include notation and remove -Iinclude/drm flag

Include <drm/*.h> instead of relative path from include/drm, then
remove the -Iinclude/drm compiler flag.

While we are here, use <...> instead of "..." for include/linux/*.h
and include/sound/*.h headers too.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1495081793-9707-2-git-send-email-yamada.masahiro@socionext.com

drivers/gpu/drm/vc4/vc4_plane.c

@@ -18,12 +18,13 @@
  * into the region of the HVS that it has allocated for us.
  */
 
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_plane_helper.h>
+
 #include "vc4_drv.h"
 #include "vc4_regs.h"
-#include "drm_atomic.h"
-#include "drm_atomic_helper.h"
-#include "drm_fb_cma_helper.h"
-#include "drm_plane_helper.h"
 
 enum vc4_scaling_mode {
 	VC4_SCALING_NONE,