armv8/ls2085aqds: NAND boot support

This adds NAND boot support for LS2085AQDS, using SPL framework.
Details of forming NAND image can be found in README.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[York Sun: Remove +S from defconfig after commit 252ed872]
Signed-off-by: York Sun <yorksun@freescale.com>
15 files changed