backlight: Remove bogus SYSFS dependency

Remove a bogus SYSFS dependency from the backlight class

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 6801edf..1b79a6f 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -12,7 +12,7 @@
 
 obj-$(CONFIG_VT)		  += console/
 obj-$(CONFIG_LOGO)		  += logo/
-obj-$(CONFIG_SYSFS)		  += backlight/
+obj-y				  += backlight/
 
 obj-$(CONFIG_FB_CFB_FILLRECT)  += cfbfillrect.o
 obj-$(CONFIG_FB_CFB_COPYAREA)  += cfbcopyarea.o