iio:dac: Add support for the AD7303

This patch adds support for the AD7303. The AD7303 is a simple 2 channel 8 bit
DAC with an SPI interface.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index b61160b..c9c33ce 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -130,6 +130,16 @@
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5686.
 
+config AD7303
+	tristate "Analog Devices Analog Devices AD7303 DAC driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD7303 Digital to Analog
+	  Converters (DAC).
+
+	  To compile this driver as module choose M here: the module will be called
+	  ad7303.
+
 config MAX517
 	tristate "Maxim MAX517/518/519 DAC driver"
 	depends on I2C