GPIO: Add support for GPIO on CLPS711X-target platform

The CLPS711X CPUs provide some GPIOs for use in the system. This
driver provides support for these via gpiolib. Due to platform
limitations, driver does not support interrupts, only inputs and
outputs.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>