gpio: make any OF dependent driver depend on OF_GPIO

The drivers that depend on OF but not OF_GPIO are wreaking havoc
with the autobuilders for archs that have all requirements for
OF but not for OF_GPIO, particularly the UM (Usermode) arch does
not have iomem (NO_IOMEM) which result in configuring GPIOLIB but
without OF_GPIO which is wrong if the driver is using the .of_node
of the gpiochip, which only appears with OF_GPIO.

After a brief look at the drivers just depending on OF it seems
most if not all of them actually require stuff from gpiolib-of so
the dependency is wrong in the first place.

This simply patches the Kconfig so that all GPIO drivers using OF
depend on OF_GPIO rather than just OF.

Cc: Rabin Vincent <rabin@rab.in>
Cc: Pramod Gurav <pramod.gurav@smartplayin.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Phil Reid <preid@electromag.com.au>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>