sensor: add driver for LIS3MDL magnetometer

Add driver for the LIS3MDL ultra-low-power high-performance three-axis
magnetic sensor.

Datasheet:
	http://www.st.com/resource/en/datasheet/lis3mdl.pdf

Application note:
	http://www.st.com/resource/en/application_note/dm00136626.pdf



Change-Id: Id2d65e7525bef6c4fe50f86169a80f84197f8983
Origin: Original
Signed-off-by: Bogdan Davidoaia <bogdan.m.davidoaia@intel.com>