cs5535-gpio: add AMD CS5535/CS5536 GPIO driver support

This creates a CS5535/CS5536 GPIO driver which uses a gpio_chip backend
(allowing GPIO users to use the generic GPIO API if desired) while also
allowing architecture-specific users directly (via the cs5535_gpio_*
functions).

Tested on an OLPC machine.  Some Leemotes also use CS5536 (with a mips
cpu), which is why this is in drivers/gpio rather than arch/x86.
Currently, it conflicts with older geode GPIO support; once MFGPT support
is reworked to also be more generic, the older geode code will be removed.

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>
Cc: David Brownell <david-b@pacbell.net>
Reviewed-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 00a532c..270b6d7 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -16,6 +16,7 @@
 obj-$(CONFIG_GPIO_TWL4030)	+= twl4030-gpio.o
 obj-$(CONFIG_GPIO_UCB1400)	+= ucb1400_gpio.o
 obj-$(CONFIG_GPIO_XILINX)	+= xilinx_gpio.o
+obj-$(CONFIG_GPIO_CS5535)	+= cs5535-gpio.o
 obj-$(CONFIG_GPIO_BT8XX)	+= bt8xxgpio.o
 obj-$(CONFIG_GPIO_VR41XX)	+= vr41xx_giu.o
 obj-$(CONFIG_GPIO_WM831X)	+= wm831x-gpio.o