drm/tilcdc: 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.
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/1493009447-31524-15-git-send-email-yamada.masahiro@socionext.com

drivers/gpu/drm/tilcdc/Makefile

-ccflags-y := -Iinclude/drm
 ifeq (, $(findstring -W,$(EXTRA_CFLAGS)))
 	ccflags-y += -Werror
 endif

drivers/gpu/drm/tilcdc/tilcdc_drv.c

@@ -22,6 +22,7 @@
 #include <linux/suspend.h>
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_fb_helper.h>
 
 #include "tilcdc_drv.h"
 #include "tilcdc_regs.h"
@@ -29,8 +30,6 @@
 #include "tilcdc_panel.h"
 #include "tilcdc_external.h"
 
-#include "drm_fb_helper.h"
-
 static LIST_HEAD(module_list);
 
 static const u32 tilcdc_rev1_formats[] = { DRM_FORMAT_RGB565 };