gpiolib: quiet gpiochip_add boot message noise

The pr_info message in gpiochip_add gets displayed for every
gpiochip registered. When first bringing up a system this
information could be helpful but for normal use it's just a
bunch of noise. Change the message to a pr_debug.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/gpio/gpiolib.c

@@ -1093,7 +1093,7 @@ unlock:
 	if (status)
 		goto fail;
 
-	pr_info("gpiochip_add: registered GPIOs %d to %d on device: %s\n",
+	pr_debug("gpiochip_add: registered GPIOs %d to %d on device: %s\n",
 		chip->base, chip->base + chip->ngpio - 1,
 		chip->label ? : "generic");