Create new layer for recipes and files that required only when
meta-fsl-arm and meta-fsl-arm-extra layers are used. For now,
the bblayers.conf template still includes the new layer as well.

Change-Id: I01a0019ebaea3e1532f106e076f7608fb7aa86c6
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@digia.com>