drm/amd/display: Remove unused panel patch "disconnect_delay"

[Why]
This patch is for use by dm, no need for it in dc.
Signed-off-by: Joshua Aberback <joshua.aberback@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -191,7 +191,6 @@ union display_content_support {
 };
 
 struct dc_panel_patch {
-	unsigned int disconnect_delay;
 	unsigned int dppowerup_delay;
 	unsigned int extra_t12_ms;
 };