ARM: 7042/3: mach-ep93xx: break out GPIO driver specifics

The <mach/gpio.h> file is included from upper directories
and deal with generic GPIO and gpiolib stuff. Break out the
platform and driver specific defines and functions into its own
header file.

Cc: Ryan Mallon <rmallon@gmail.com>
Acked-by: Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/gpio/gpio-ep93xx.c b/drivers/gpio/gpio-ep93xx.c
index fbd6a60..7aafbb4 100644
--- a/drivers/gpio/gpio-ep93xx.c
+++ b/drivers/gpio/gpio-ep93xx.c
@@ -23,6 +23,9 @@
 #include <linux/basic_mmio_gpio.h>
 
 #include <mach/hardware.h>
+#include <mach/gpio-ep93xx.h>
+
+#define irq_to_gpio(irq)	((irq) - gpio_to_irq(0))
 
 struct ep93xx_gpio {
 	void __iomem		*mmio_base;