ixp4xx: fix compilation by adding gpiolib support

commit 9dde0ae3769875ec1370cb316e50c54b57d52c1a upstream.

Once again, ixp4xx no longer even compiles. This patch fixes the issue
by converting over to gpiolib. This patch was first made by Imre and
posted by Marc, and I added in Russell's suggestion to empty the gpio
header file.

This fix should also go for 3.1, 3.2, 3.3, and 3.4.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 36586dba..7a8660a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -556,7 +556,7 @@
 	select ARCH_HAS_DMA_SET_COHERENT_MASK
 	select CLKSRC_MMIO
 	select CPU_XSCALE
-	select GENERIC_GPIO
+	select ARCH_REQUIRE_GPIOLIB
 	select GENERIC_CLOCKEVENTS
 	select MIGHT_HAVE_PCI
 	select NEED_MACH_IO_H