The board is able to boot from the following source:
- user-updateble SPI flash
- write-protected part of the same SPI flash
- eMMC
- SD card
Implement the needed function hooks to support all of these boot
sources.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Peng Fan <peng.fan@nxp.com>