sample: Add IMX IPM sample application

Add IMX IPM sample application. It reads the data sent to the
Messaging Unit and sends them back. It has been tested on Udoo Neo Full
board with the Cortex-A9 core running Linux and sending the data
into the Messaging Unit A and the Cortex-M4 running this sample Zephyr
application and reading the data from Messaging Unit B and sending it
back for Linux side to read it from Messaging Unit A.

Origin: Original

Signed-off-by: Stanislav Poboril <stanislav.poboril@nxp.com>