Without loading the igb at boot, the recovery wouldn't have
network available. All network drivers should be loaded before
etc/board.d/02_network is called. Note that other network drivers
already have this set, such as tg3.
Fixes: 7e0e5110bc90 ("kernel: add igb kernel module")
Signed-off-by: Chris Blake <chrisrblake93@gmail.com>