First steps to build Yocto image for SabreSD
(MACHINE=imx6qsabresd)

Signed-off-by: Gianpaolo Macario <gianpaolo_macario@mentor.com>
README.md: Add results for MACHINE=imx6qsabresh
Merge pull request #28 from gmacario/build-yocto-sabresd

Build Yocto distro for Freescale Sabre Board for Smart Devices (imx6qsabresd)