drm/hisilicon: 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/1493009447-31524-9-git-send-email-yamada.masahiro@socionext.com

drivers/gpu/drm/hisilicon/hibmc/Makefile

-ccflags-y := -Iinclude/drm
 hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_drm_fbdev.o hibmc_ttm.o
 
 obj-$(CONFIG_DRM_HISI_HIBMC) += hibmc-drm.o

drivers/gpu/drm/hisilicon/hibmc/hibmc_ttm.c

@@ -17,7 +17,7 @@
  */
 
 #include <drm/drm_atomic_helper.h>
-#include <ttm/ttm_page_alloc.h>
+#include <drm/ttm/ttm_page_alloc.h>
 
 #include "hibmc_drm_drv.h"