drm/sched: remove unneeded -Iinclude/drm compiler flag

I refactored the include directives under include/drm/ some time ago.
This flag is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/scheduler/Makefile

@@ -20,7 +20,6 @@
 # OTHER DEALINGS IN THE SOFTWARE.
 #
 #
-ccflags-y := -Iinclude/drm
 gpu-sched-y := gpu_scheduler.o sched_fence.o
 
 obj-$(CONFIG_DRM_SCHED) += gpu-sched.o