drm/amd/display: remove unused function dc_link_perform_link_training

This function is not used anywhere, remove it. It was added in
40dd6bd3 ("drm/amd/display: Linux Set/Read link rate and lane count
through debugfs") and moved in fe798de5 ("drm/amd/display: Move link
functions from dc to dc_link"), but a user is missing.
Reviewed-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NRouven Czerwinski <r.czerwinski@pengutronix.de>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -3578,19 +3578,6 @@ void dc_link_set_drive_settings(struct dc *dc,
 	dc_link_dp_set_drive_settings(dc->links[i], lt_settings);
 }
 
-void dc_link_perform_link_training(struct dc *dc,
-				   struct dc_link_settings *link_setting,
-				   bool skip_video_pattern)
-{
-	int i;
-
-	for (i = 0; i < dc->link_count; i++)
-		dc_link_dp_perform_link_training(
-			dc->links[i],
-			link_setting,
-			skip_video_pattern);
-}
-
 void dc_link_set_preferred_link_settings(struct dc *dc,
 					 struct dc_link_settings *link_setting,
 					 struct dc_link *link)

drivers/gpu/drm/amd/display/dc/dc_link.h

@@ -356,9 +356,6 @@ bool dc_link_is_hdcp22(struct dc_link *link, enum signal_type signal);
 void dc_link_set_drive_settings(struct dc *dc,
 				struct link_training_settings *lt_settings,
 				const struct dc_link *link);
-void dc_link_perform_link_training(struct dc *dc,
-				   struct dc_link_settings *link_setting,
-				   bool skip_video_pattern);
 void dc_link_set_preferred_link_settings(struct dc *dc,
 					 struct dc_link_settings *link_setting,
 					 struct dc_link *link);