backlight: generic_bl: Remove unused function

genericbl_limit_intensity() is exported, but it is never
called anywhere else.

Fix the following sparse warning:

drivers/video/backlight/generic_bl.c:59:6:
  warning: symbol 'genericbl_limit_intensity' was not declared.
  Should it be static?
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/video/backlight/generic_bl.c

@@ -52,24 +52,6 @@ static int genericbl_get_intensity(struct backlight_device *bd)
 	return genericbl_intensity;
 }
 
-/*
- * Called when the battery is low to limit the backlight intensity.
- * If limit==0 clear any limit, otherwise limit the intensity
- */
-void genericbl_limit_intensity(int limit)
-{
-	struct backlight_device *bd = generic_backlight_device;
-
-	mutex_lock(&bd->ops_lock);
-	if (limit)
-		bd->props.state |= GENERICBL_BATTLOW;
-	else
-		bd->props.state &= ~GENERICBL_BATTLOW;
-	backlight_update_status(generic_backlight_device);
-	mutex_unlock(&bd->ops_lock);
-}
-EXPORT_SYMBOL(genericbl_limit_intensity);
-
 static const struct backlight_ops genericbl_ops = {
 	.options = BL_CORE_SUSPENDRESUME,
 	.get_brightness = genericbl_get_intensity,