board: sl28: support dynamic prompts

Depending on the boot source, set different CLI prompts. This will help
the user to figure out in which mode the bootloader was started. There
are two special modes: failsafe and SDHC boot.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
2 files changed