mb/siemens/mc_apl1: Simplify is_mac_adr_valid() logic
A MAC address that is neither 00:00:00:00:00:00 nor ff:ff:ff:ff:ff:ff is
considered valid. Instead of using a temporary buffer and memcmp(), use
a single loop that exits as soon as the MAC cannot possibly be invalid.
Change-Id: I2b15b510092860fbbefd150c9060da38aeb13311
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47405
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-by: Uwe Poeche <uwe.poeche@siemens.com>