drm/amdgpu: add backend implementation of gpu scheduler (v2)

v2: fix rebase breakage

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Acked-by: Christian K?nig <christian.koenig@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/Makefile b/drivers/gpu/drm/amd/amdgpu/Makefile
index 2800cf7..f1cb7d2 100644
--- a/drivers/gpu/drm/amd/amdgpu/Makefile
+++ b/drivers/gpu/drm/amd/amdgpu/Makefile
@@ -85,7 +85,8 @@
 
 # GPU scheduler
 amdgpu-y += \
-	../scheduler/gpu_scheduler.o
+	../scheduler/gpu_scheduler.o \
+	amdgpu_sched.o
 
 amdgpu-$(CONFIG_COMPAT) += amdgpu_ioc32.o
 amdgpu-$(CONFIG_VGA_SWITCHEROO) += amdgpu_atpx_handler.o