On i.MX7ULP, the fuse words (except bank 0 and 1) only supports to
write once, because they use ECC mode. Multiple writes may damage
the ECC value and cause a wrong fuse value decoded when reading.
This patch adds a checking before the fuse word programming, only
can write when the word value is 0.
Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>