drm/ast: 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/1493009447-31524-5-git-send-email-yamada.masahiro@socionext.com

drivers/gpu/drm/ast/Makefile

@@ -2,8 +2,6 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
-ccflags-y := -Iinclude/drm
-
 ast-y := ast_drv.o ast_main.o ast_mode.o ast_fb.o ast_ttm.o ast_post.o ast_dp501.o
 
 obj-$(CONFIG_DRM_AST) := ast.o

drivers/gpu/drm/ast/ast_ttm.c

@@ -26,8 +26,9 @@
  * Authors: Dave Airlie <airlied@redhat.com>
  */
 #include <drm/drmP.h>
+#include <drm/ttm/ttm_page_alloc.h>
+
 #include "ast_drv.h"
-#include <ttm/ttm_page_alloc.h>
 
 static inline struct ast_private *
 ast_bdev(struct ttm_bo_device *bd)