drm/amd/display: Add struct field for future use

Add dmub related struct field for future use.

Signed-off-by: Anthony Koo <[e-mail]>
Reviewed-by: Anthony Koo <[e-mail]>
Acked-by: Aurabindo Pillai <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h

···
 	uint32_t ramping_boundary;
 	uint32_t otg_inst;
 	uint32_t panel_inst;
+	uint32_t set_pipe_option;
 };
 
 struct dmub_rb_cmd_abm_set_pipe {