drm/amd/powerplay: Delete dead struct declaration

Signed-off-by: NNils Wallménius <nils.wallmenius@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -29,7 +29,6 @@
 
 extern int cz_phm_set_asic_block_gating(struct pp_hwmgr *hwmgr, enum PHM_AsicBlock block, enum PHM_ClockGateSetting gating);
 extern const struct phm_master_table_header cz_phm_enable_clock_power_gatings_master;
-extern struct phm_master_table_header cz_phm_disable_clock_power_gatings_master;
 extern int cz_dpm_powergate_vce(struct pp_hwmgr *hwmgr, bool bgate);
 extern int cz_dpm_powergate_uvd(struct pp_hwmgr *hwmgr, bool bgate);
 extern int cz_enable_disable_vce_dpm(struct pp_hwmgr *hwmgr, bool enable);