drm/amdgpu: add raven case for gmc9 golden setting

Golden settings for GMC9.
Signed-off-by: NChunming Zhou <David1.Zhou@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -686,6 +686,8 @@ static void gmc_v9_0_init_golden_registers(struct amdgpu_device *adev)
 	switch (adev->asic_type) {
 	case CHIP_VEGA10:
 		break;
+	case CHIP_RAVEN:
+		break;
 	default:
 		break;
 	}