On AHB, the calibration data usually does not contain a valid MAC address,
the correct MAC address is stored in the board config.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>