gpio: altera-a10sr: Add A10 System Resource Chip GPIO support.

Add the GPIO functionality for the Altera Arria10 MAX5 System Resource
Chip. The A10 MAX5 has 12 bits of GPIO assigned to switches, buttons,
and LEDs as a GPIO extender on the SPI bus.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>i
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 26ee00f..41e2a8f 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -818,6 +818,14 @@
 	  This option enables support for on-chip GPIO found
 	  on Analog Devices ADP5520 PMICs.
 
+config GPIO_ALTERA_A10SR
+	tristate "Altera Arria10 System Resource GPIO"
+	depends on MFD_ALTERA_A10SR
+	help
+	  Driver for Arria10 Development Kit GPIO expansion which
+	  includes reads of pushbuttons and DIP switches as well
+	  as writes to LEDs.
+
 config GPIO_ARIZONA
 	tristate "Wolfson Microelectronics Arizona class devices"
 	depends on MFD_ARIZONA