drm/amd/display: fix accidental casting enum to bool

[why/how]
Fixing -Wint-in-bool-context Clang Build Failure
Reviewed-by: Nicholas Choi <Nicholas.Choi@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c

@@ -584,7 +584,7 @@ bool dm_helpers_dp_write_dsc_enable(
 		ret = drm_dp_dpcd_write(aconnector->dsc_aux, DP_DSC_ENABLE, &enable_dsc, 1);
 	}
 
-	if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT || SIGNAL_TYPE_EDP) {
+	if (stream->signal == SIGNAL_TYPE_DISPLAY_PORT || stream->signal == SIGNAL_TYPE_EDP) {
 		ret = dm_helpers_dp_write_dpcd(ctx, stream->link, DP_DSC_ENABLE, &enable_dsc, 1);
 		DC_LOG_DC("Send DSC %s to sst display\n", enable_dsc ? "enable" : "disable");
 	}