iio: add driver for Freescale MMA9551L

Add support for Freescale MMA9551L Intelligent Motion-Sensing Platform.
The driver supports raw reads for acceleration and inclination, as well
as configuring inclination rate-of-change events.  The events can be
used similarly to an Android sensor Tilt event.

The specifications can be downloaded from:
http://www.freescale.com/files/sensors/doc/ref_manual/MMA955xLSWRM.pdf

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Vlad Dogaru <vlad.dogaru@intel.com>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 9b9be87..d80616d 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -105,4 +105,14 @@
 	  To compile this driver as a module, choose M here: the module will
 	  be called kxcjk-1013.
 
+config MMA9551
+	tristate "Freescale MMA9551L Intelligent Motion-Sensing Platform Driver"
+	depends on I2C
+	help
+	  Say yes here to build support for the Freescale MMA9551L
+	  Intelligent Motion-Sensing Platform Driver.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called mma9551.
+
 endmenu