drm/amdgpu: amdgpu_kiq_reg_write_reg_wait() can be static

Fixes: d790449835e6 ("drm/amdgpu: use kiq to do invalidate tlb")
Reviewed-by: NEmily Deng <Emily.Deng@amd.com>
Signed-off-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -311,7 +311,7 @@ static uint32_t gmc_v9_0_get_invalidate_req(unsigned int vmid)
 	return req;
 }
 
-signed long  amdgpu_kiq_reg_write_reg_wait(struct amdgpu_device *adev,
+static signed long  amdgpu_kiq_reg_write_reg_wait(struct amdgpu_device *adev,
 						  uint32_t reg0, uint32_t reg1,
 						  uint32_t ref, uint32_t mask)
 {