docs: nxp soc-lx2160a based platforms

Addition of documents for platforms based on
NXP SoC LX2160A.

Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Change-Id: I39ac5a9eb0b668d26301a0a24a1e6bf87f245f02
5 files changed