backlight: Add backlight_device parameter to check_fb

check_fb from backlight_ops lacks a reference to the backlight_device
that's being referred to. Add this parameter so a backlight_device
can be mapped to a single framebuffer, especially if the same driver
handles multiple devices on a single system.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 18829cf..b800cd4 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -38,7 +38,7 @@
 	mutex_lock(&bd->ops_lock);
 	if (bd->ops)
 		if (!bd->ops->check_fb ||
-		    bd->ops->check_fb(evdata->info)) {
+		    bd->ops->check_fb(bd, evdata->info)) {
 			bd->props.fb_blank = *(int *)evdata->data;
 			if (bd->props.fb_blank == FB_BLANK_UNBLANK)
 				bd->props.state &= ~BL_CORE_FBBLANK;