drm/amd/display: Remove unnecessary DSC power gating for DCN401

[Why]
In some cases during topology changes, a pipe that was used to drive a
stream being removed can be re-assigned to drive a different stream. In
these cases, DSC power gating is not handled properly, leading to
situations where DSC is being setup while power gated.

[How]
 - remove enable_stream_gating and disable_stream_gating for DCN401

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo@amd.com>
Signed-off-by: Joshua Aberback <joshua.aberback@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_init.c

@@ -115,8 +115,6 @@ static const struct hwseq_private_funcs dcn401_private_funcs = {
 	.reset_hw_ctx_wrap = dcn20_reset_hw_ctx_wrap,
 	.enable_stream_timing = dcn401_enable_stream_timing,
 	.edp_backlight_control = dce110_edp_backlight_control,
-	.disable_stream_gating = dcn20_disable_stream_gating,
-	.enable_stream_gating = dcn20_enable_stream_gating,
 	.setup_vupdate_interrupt = dcn20_setup_vupdate_interrupt,
 	.did_underflow_occur = dcn10_did_underflow_occur,
 	.init_blank = dcn32_init_blank,