drm/amd/powerplay: add new function point in hwmgr_func for CG/PG.

BugLink: http://bugs.launchpad.net/bugs/1546572

Add callbacks interface for clock and powergating.
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit b1132013)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/gpu/drm/amd/powerplay/inc/hwmgr.h

@@ -289,6 +289,9 @@ struct pp_hwmgr_func {
 	int (*enable_clock_power_gating)(struct pp_hwmgr *hwmgr);
 	int (*notify_smc_display_config_after_ps_adjustment)(struct pp_hwmgr *hwmgr);
 	int (*display_config_changed)(struct pp_hwmgr *hwmgr);
+	int (*disable_clock_power_gating)(struct pp_hwmgr *hwmgr);
+	int (*update_clock_gatings)(struct pp_hwmgr *hwmgr,
+						const uint32_t *msg_id);
 };
 
 struct pp_table_func {