drm/amd/pm/powerplay/hwmgr/hardwaremanager: Remove unused 'phm_set_*()' functions

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/hardwaremanager.c:518:5: warning: no previous prototype for ‘phm_set_min_deep_sleep_dcefclk’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/hardwaremanager.c:528:5: warning: no previous prototype for ‘phm_set_hard_min_dcefclk_by_freq’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/hardwaremanager.c:538:5: warning: no previous prototype for ‘phm_set_hard_min_fclk_by_freq’ [-Wmissing-prototypes]

Cc: Evan Quan <evan.quan@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -514,34 +514,3 @@ int phm_set_active_display_count(struct pp_hwmgr *hwmgr, uint32_t count)
 
 	return hwmgr->hwmgr_func->set_active_display_count(hwmgr, count);
 }
-
-int phm_set_min_deep_sleep_dcefclk(struct pp_hwmgr *hwmgr, uint32_t clock)
-{
-	PHM_FUNC_CHECK(hwmgr);
-
-	if (!hwmgr->hwmgr_func->set_min_deep_sleep_dcefclk)
-		return -EINVAL;
-
-	return hwmgr->hwmgr_func->set_min_deep_sleep_dcefclk(hwmgr, clock);
-}
-
-int phm_set_hard_min_dcefclk_by_freq(struct pp_hwmgr *hwmgr, uint32_t clock)
-{
-	PHM_FUNC_CHECK(hwmgr);
-
-	if (!hwmgr->hwmgr_func->set_hard_min_dcefclk_by_freq)
-		return -EINVAL;
-
-	return hwmgr->hwmgr_func->set_hard_min_dcefclk_by_freq(hwmgr, clock);
-}
-
-int phm_set_hard_min_fclk_by_freq(struct pp_hwmgr *hwmgr, uint32_t clock)
-{
-	PHM_FUNC_CHECK(hwmgr);
-
-	if (!hwmgr->hwmgr_func->set_hard_min_fclk_by_freq)
-		return -EINVAL;
-
-	return hwmgr->hwmgr_func->set_hard_min_fclk_by_freq(hwmgr, clock);
-}
-