Add support for more nic drivers to netboot.

Signed-off-by: Jorge Manuel B. S. Vicetto (jmbsvicetto) <jmbsvicetto@gentoo.org>
Add support for more nic drivers to netboot - forgot to add x86_64 config.

Signed-off-by: Jorge Manuel B. S. Vicetto (jmbsvicetto) <jmbsvicetto@gentoo.org>