[ARM] pxa/magician: default to backlight trigger for keypad illumination

Default to the same behaviour as the shipped WinCE system.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>

arch/arm/mach-pxa/magician.c

@@ -435,7 +435,7 @@ static struct gpio_led gpio_leds[] = {
 	},
 	{
 		.name = "magician::phone_bl",
-		.default_trigger = "none",
+		.default_trigger = "backlight",
 		.gpio = GPIO103_MAGICIAN_LED_KP,
 	},
 };