[ARM] 4988/1: Add GPIO lib support to the EP93xx

Adds support for the generic GPIO lib to the EP93xx family. The gpio
handling code has been moved from core.c to a new file called gpio.c.
The GPIO based IRQ code has not been changed.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 4039a13..a583c0b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -255,6 +255,7 @@
 	select ARM_AMBA
 	select ARM_VIC
 	select GENERIC_GPIO
+	select HAVE_GPIO_LIB
 	help
 	  This enables support for the Cirrus EP93xx series of CPUs.