drm/amd/pp: Delete duplicated interface in hwmgr_func

gfx off support in smu can be via powergate_gfx interface.
so remove the gfx_off_control interface.

Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c

@@ -1185,7 +1185,6 @@ static const struct pp_hwmgr_func smu10_hwmgr_funcs = {
 	.dynamic_state_management_disable = smu10_disable_dpm_tasks,
 	.powergate_mmhub = smu10_powergate_mmhub,
 	.smus_notify_pwe = smu10_smus_notify_pwe,
-	.gfx_off_control = smu10_gfx_off_control,
 	.display_clock_voltage_request = smu10_display_clock_voltage_request,
 	.powergate_gfx = smu10_gfx_off_control,
 };

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

@@ -298,7 +298,6 @@ struct pp_hwmgr_func {
 	int (*display_clock_voltage_request)(struct pp_hwmgr *hwmgr,
 			struct pp_display_clock_request *clock);
 	int (*get_max_high_clocks)(struct pp_hwmgr *hwmgr, struct amd_pp_simple_clock_info *clocks);
-	int (*gfx_off_control)(struct pp_hwmgr *hwmgr, bool enable);
 	int (*power_off_asic)(struct pp_hwmgr *hwmgr);
 	int (*force_clock_level)(struct pp_hwmgr *hwmgr, enum pp_clock_type type, uint32_t mask);
 	int (*print_clock_levels)(struct pp_hwmgr *hwmgr, enum pp_clock_type type, char *buf);