[ARM] 5510/1: U300 GPIO debug and init fixes

This moves the GPIO driver away from using __devinit and __devexit
It also removes all printk() in favor of using dev_* print macros
on pdev->dev struct instead. Surplus prints are removed, and the
platform_device_probe() function is used instead of putting a
.probe function in the platform driver struct.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>