backlight: fix blanking for L4F00242T03 LCD

The LCD was turned on if the variable power was > 0, but that was
incorrect.  The LCD has to be turned on in NORMAL and UNBLANK case.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/l4f00242t03.c

@@ -78,7 +78,7 @@ static int l4f00242t03_lcd_power_set(struct lcd_device *ld, int power)
 	const u16 slpin = 0x10;
 	const u16 disoff = 0x28;
 
-	if (power) {
+	if (power <= FB_BLANK_NORMAL) {
 		if (priv->lcd_on)
 			return 0;