drm/amd/display: remove set but not used variable 'ds_port'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c: In function dp_wa_power_up_0010FA:
drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:2320:35: warning:
 variable ds_port set but not used [-Wunused-but-set-variable]

It is never used, so can be removed.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -2910,7 +2910,6 @@ static void dp_wa_power_up_0010FA(struct dc_link *link, uint8_t *dpcd_data,
 		int length)
 {
 	int retry = 0;
-	union dp_downstream_port_present ds_port = { 0 };
 
 	if (!link->dpcd_caps.dpcd_rev.raw) {
 		do {
@@ -2923,9 +2922,6 @@ static void dp_wa_power_up_0010FA(struct dc_link *link, uint8_t *dpcd_data,
 		} while (retry++ < 4 && !link->dpcd_caps.dpcd_rev.raw);
 	}
 
-	ds_port.byte = dpcd_data[DP_DOWNSTREAMPORT_PRESENT -
-				 DP_DPCD_REV];
-
 	if (link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_VGA_CONVERTER) {
 		switch (link->dpcd_caps.branch_dev_id) {
 		/* 0010FA active dongles (DP-VGA, DP-DLDVI converters) power down