pinctrl/ARM: move GPIO and pinctrl deps to device tree

This gets the GPIO ranges out of the driver and into the device
tree where they belong. Standard DT bindings already exist for
this. Since no systems with this are deployed we can just augment
all device trees and the drivers at the same time and simplify
the world.

This also defines the array of GPIO chips related to the pin
controller.

Cc: arm@kernel.org
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>