gpiolib: Add support for Wolfson Microelectronics Arizona class devices

The Arizona class devices provide some GPIOs for use in the system. This
driver provides support for these via gpiolib. Currently interrupts are
not supported, normally the GPIOs are outputs only.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[Fold in WM5110 support patch]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>