drm/amd/display: Add a PP_SMU_VER_MAX enum

Signed-off-by: NJun Lei <Jun.Lei@amd.com>
Reviewed-by: NNevenko Stupar <Nevenko.Stupar@amd.com>
Acked-by: NLeo Li <sunpeng.li@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dm_pp_smu.h

@@ -38,7 +38,8 @@ enum pp_smu_ver {
 	 * of interface sharing between families of ASIcs.
 	 */
 	PP_SMU_UNSUPPORTED,
-	PP_SMU_VER_RV
+	PP_SMU_VER_RV,
+	PP_SMU_VER_MAX
 };
 
 struct pp_smu {