OMAPDSS: Add missing dependency on backlight for DSI-CM panel drier

The DSI-CM driver uses the backlight class so needs to build depend on it.
Signed-off-by: NMark Brown <broonie@linaro.org>
Reviewed-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/displays-new/Kconfig

@@ -35,6 +35,7 @@ config DISPLAY_PANEL_DPI
 
 config DISPLAY_PANEL_DSI_CM
 	tristate "Generic DSI Command Mode Panel"
+	depends on BACKLIGHT_CLASS_DEVICE
 	help
 	  Driver for generic DSI command mode panels.