fbdev: sh_mobile_lcdc: Make sh_mobile_lcdc_sys_bus_ops static

The structure isn't used outside of its compilation unit, make it
static.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/video/sh_mobile_lcdcfb.c

@@ -438,7 +438,7 @@ static unsigned long lcdc_sys_read_data(void *handle)
 	return lcdc_read(ch->lcdc, _LDDRDR) & LDDRDR_DRD_MASK;
 }
 
-struct sh_mobile_lcdc_sys_bus_ops sh_mobile_lcdc_sys_bus_ops = {
+static struct sh_mobile_lcdc_sys_bus_ops sh_mobile_lcdc_sys_bus_ops = {
 	lcdc_sys_write_index,
 	lcdc_sys_write_data,
 	lcdc_sys_read_data,