leds: as3645a: Fix quoted string split warning

Fix a warning for a split quoted string across
lines.

WARNING: quoted string split across lines
459: FILE: drivers/leds/leds-as3645a.c:459:
		dev_err(dev, "AS3645A not detected "
			"(model %d rfu %d)\n", model, rfu);

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>