arm64: a8k: dts: Add support for NAND devices on A8K platform
Add NAND to CP master device tree. Add armada-7040-db-nand
device tree for the board configured with NAND boot device.
Add comment about boot device ID to armada-7040-db DTS.
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com> Cc: Stefan Roese <sr@denx.de> Cc: Igal Liberman <igall@marvell.com> Cc: Nadav Haklai <nadavh@marvell.com> Reviewed-by: Stefan Roese <sr@denx.de>