ramips: fix Ethernet random MAC address for HILINK HLK-7628N

ramips: fix Ethernet random MAC address for HILINK HLK-7628N

Set the ethernet address from flash.

MAC addresses as verified by OEM firmware:

  use   interface  source
  2g    wlan0      factory 0x04 (label)
  LAN   eth0.1     factory 0x28 (label+1)
  WAN   eth0.2     factory 0x2e (label+2)

Fixes: 671c9d16e382 ("ramips: add support for HILINK HLK-7628N")
Signed-off-by: Liu Yu <f78fk@live.com>
[drop old MAC address setup from 02_network, cut out state_default
changes, face-lift commit message, add Fixes:]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
(cherry picked from commit ae9c5cd37bf5c08452f314b54afa963a00bdde30)