gpio: Move DT support code into drivers/gpio

The code in drivers/of/gpio.c isn't shared by any other subsystem since it
is all gpiolib specific.  drivers/gpio is a better place to maintain these
functions.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e6862f1..1042c3f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -37,6 +37,10 @@
 
 if GPIOLIB
 
+config OF_GPIO
+	def_bool y
+	depends on OF && !SPARC
+
 config DEBUG_GPIO
 	bool "Debug GPIO calls"
 	depends on DEBUG_KERNEL