Enables e1000 Ethernet device as it is used as a low-cost failover
Ethernet port on various QorIQ reference boards.  Enabled as built-in
for booting from network without initramfs.
Signed-off-by: NLi Yang <leoyang.li@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>