collie: locomo-led change default trigger

Collie uses now the powersupply framework. Change the
default led-trigger of locomo-led to reflect that.

drivers/leds/leds-locomo.c

···
 
 static struct led_classdev locomo_led0 = {
 	.name			= "locomo:amber:charge",
-	.default_trigger	= "sharpsl-charge",
+	.default_trigger	= "main-battery-charging",
 	.brightness_set		= locomoled_brightness_set0,
 };