drm/amdgpu: release_pages requires linux/pagemap.h

Signed-off-by: Stephen Rothwell <[e-mail]>
Reviewed-by: Christian König <[e-mail].
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

···
  *    Jerome Glisse <[e-mail]>
  */
 #include <linux/list_sort.h>
+#include <linux/pagemap.h>
 #include <drm/drmP.h>
 #include <drm/amdgpu_drm.h>
 #include "amdgpu.h"

drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c

···
  *          Jerome Glisse
  */
 #include <linux/ktime.h>
+#include <linux/pagemap.h>
 #include <drm/drmP.h>
 #include <drm/amdgpu_drm.h>
 #include "amdgpu.h"