ARM: dts: sa2150p: add support for NAND based SOM

This commit adds initial device tree required for sa2150p
based SOM having NAND storage.

Although the SoC is quad core but it is made to operate
in dual core mode as board's PDN specifications are
exceeded.

Change-Id: Ie32687222e817b325833e55dd9cc16477ced7e5c
Signed-off-by: Rishi Gupta <rishgupt@codeaurora.org>