iio: accel: Add driver for the MiraMEMS DA280 3-axis 14-bit digital accelerometer

Add an iio driver for the MiraMEMS DA280 3-axis 14-bit accelerometer, as
well as for the DA226 which is a fully compatible 2-axis version.

Datasheets for the DA280 and DA226 can be found at the manufacturers site:
http://www.miramems.com/en/products.asp?list=1

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 8945e70..878e3c9 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -52,6 +52,16 @@
 	tristate
 	select REGMAP_SPI
 
+config DA280
+	tristate "MiraMEMS DA280 3-axis 14-bit digital accelerometer driver"
+	depends on I2C
+	help
+	  Say yes here to build support for the MiraMEMS DA280 3-axis 14-bit
+	  digital accelerometer.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called da280.
+
 config DA311
 	tristate "MiraMEMS DA311 3-axis 12-bit digital accelerometer driver"
 	depends on I2C