DA8xx: add generic GPIO driver

Add a generic GPIO driver for the DaVinci DA8xx processors. It is turned
on by defining CONFIG_DA8XX_GPIO and fulfills the generic GPIO interface
specified in <asm/gpio.h> . The driver has support for both manipulating
GPIO pins as well as automatically configuring the pin multiplexor
registers to set the pin function to GPIO.

Signed-off-by: Laurence Withers <lwithers@guralp.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 1e3ae11..62ec97d 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -32,6 +32,7 @@
 COBJS-$(CONFIG_PCA953X)		+= pca953x.o
 COBJS-$(CONFIG_S5P)		+= s5p_gpio.o
 COBJS-$(CONFIG_TEGRA2_GPIO)	+= tegra2_gpio.o
+COBJS-$(CONFIG_DA8XX_GPIO)	+= da8xx_gpio.o
 
 COBJS	:= $(COBJS-y)
 SRCS 	:= $(COBJS:.o=.c)