gpio MIPS/OCTEON: Add a driver for OCTEON's on-chip GPIO pins.

The SOCs in the OCTEON family have 16 (or in some cases 20) on-chip
GPIO pins, this driver handles them all.  Configuring the pins as
interrupt sources is handled elsewhere (OCTEON's irq handling code).

Signed-off-by: David Daney <david.daney@cavium.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5633/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index ef3e983..e7fd980 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -50,6 +50,7 @@
 obj-$(CONFIG_GPIO_MVEBU)        += gpio-mvebu.o
 obj-$(CONFIG_GPIO_MXC)		+= gpio-mxc.o
 obj-$(CONFIG_GPIO_MXS)		+= gpio-mxs.o
+obj-$(CONFIG_GPIO_OCTEON)	+= gpio-octeon.o
 obj-$(CONFIG_ARCH_OMAP)		+= gpio-omap.o
 obj-$(CONFIG_GPIO_PCA953X)	+= gpio-pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= gpio-pcf857x.o