gpio: vf610: add gpiolib/IRQ chip driver for Vybrid

Add a gpiolib and IRQ chip driver for Vybrid ARM SoC using the
Vybrid's GPIO and PORT module. The driver is instanced once per
each GPIO/PORT module pair and handles 32 GPIO's.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --cc drivers/gpio/Kconfig
Simple merge

diff --cc drivers/gpio/Makefile
Simple merge

diff --cc drivers/gpio/gpio-vf610.c
Simple merge