drm/amdgpu: implement gmc_v6_0_emit_flush_gpu_tlb

Unify tlb flushing for gmc v6.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/si.h b/drivers/gpu/drm/amd/amdgpu/si.h
index 5892250..06ed721 100644
--- a/drivers/gpu/drm/amd/amdgpu/si.h
+++ b/drivers/gpu/drm/amd/amdgpu/si.h
@@ -24,6 +24,8 @@
 #ifndef __SI_H__
 #define __SI_H__
 
+#define SI_FLUSH_GPU_TLB_NUM_WREG	2
+
 void si_srbm_select(struct amdgpu_device *adev,
 		     u32 me, u32 pipe, u32 queue, u32 vmid);
 int si_set_ip_blocks(struct amdgpu_device *adev);