wifi: mt76: mt76_eeprom_override to int

mt76_eeprom_override has of_get_mac_address, which can return
-EPROBE_DEFER if the nvmem driver gets loaded after mt76 for some
reason.

Make sure this gets passed to probe so that nvmem mac overrides always
work.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://patch.msgid.link/20250911221619.16035-1-rosenp@gmail.com


Signed-off-by: Felix Fietkau <nbd@nbd.name>