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>

drivers/gpio/Kconfig

@@ -189,7 +189,7 @@ config GPIO_EP93XX
 config GPIO_ETRAXFS
 	bool "Axis ETRAX FS General I/O"
 	depends on CRIS || COMPILE_TEST
-	depends on OF
+	depends on OF_GPIO
 	select GPIO_GENERIC
 	select GPIOLIB_IRQCHIP
 	help
@@ -215,7 +215,7 @@ config GPIO_GENERIC_PLATFORM
 
 config GPIO_GRGPIO
 	tristate "Aeroflex Gaisler GRGPIO support"
-	depends on OF
+	depends on OF_GPIO
 	select GPIO_GENERIC
 	select IRQ_DOMAIN
 	help
@@ -313,7 +313,7 @@ config GPIO_MPC8XXX
 config GPIO_MVEBU
 	def_bool y
 	depends on PLAT_ORION
-	depends on OF
+	depends on OF_GPIO
 	select GENERIC_IRQ_CHIP
 
 config GPIO_MXC
@@ -406,7 +406,7 @@ config GPIO_TEGRA
 	bool "NVIDIA Tegra GPIO support"
 	default ARCH_TEGRA
 	depends on ARCH_TEGRA || COMPILE_TEST
-	depends on OF
+	depends on OF_GPIO
 	help
 	  Say yes here to support GPIO pins on NVIDIA Tegra SoCs.
 
@@ -1100,7 +1100,7 @@ menu "SPI GPIO expanders"
 
 config GPIO_74X164
 	tristate "74x164 serial-in/parallel-out 8-bits shift register"
-	depends on OF
+	depends on OF_GPIO
 	help
 	  Driver for 74x164 compatible serial-in/parallel-out 8-outputs
 	  shift registers. This driver can be used to provide access