[POWERPC] Implement support for the GPIO LIB API

This implements support for the GPIO LIB API.  Two calls are still
unimplemented though: irq_to_gpio and gpio_to_irq.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1d4d19f..c51b6bb 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -81,6 +81,11 @@
 	bool
 	default y
 
+config GENERIC_GPIO
+	bool
+	help
+	  Generic GPIO API support
+
 config ARCH_NO_VIRT_TO_BUS
 	def_bool PPC64