drm/amdgpu/powerplay: Add initial vega20 support v2

Initial powerplay support the same as vega10 for now.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NFeifei Xu <Feifei.Xu@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c

@@ -151,6 +151,7 @@ int hwmgr_early_init(struct pp_hwmgr *hwmgr)
 		hwmgr->feature_mask &= ~PP_GFXOFF_MASK;
 		switch (hwmgr->chip_id) {
 		case CHIP_VEGA10:
+		case CHIP_VEGA20:
 			hwmgr->smumgr_funcs = &vega10_smu_funcs;
 			vega10_hwmgr_init(hwmgr);
 			break;