mfd/gpio: Move HTC GPIO driver to GPIO subsystem

The HTC GPIO driver is a pure GPIO driver and I just can not
see what it is doing inside MFD. Let's just move it to GPIO
and take this opportunity to move the platform data to
<linux/platform_data/gpio-htc-egpio.h>

Cc: arm@kernel.org
Cc: Russell King <linux@armlinux.org.uk>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-sa1100/h3xxx.c

@@ -14,9 +14,9 @@
 #include <linux/gpio.h>
 #include <linux/gpio_keys.h>
 #include <linux/input.h>
-#include <linux/mfd/htc-egpio.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/platform_data/gpio-htc-egpio.h>
 #include <linux/platform_data/sa11x0-serial.h>
 #include <linux/platform_device.h>
 #include <linux/serial_core.h>