A new driver for JMicron Ethernet controller.

Reviewed-by: Joshua Oreman <oremanj@rwcr.net>
Reviewed-by: Michael Brown <mbrown@fensystems.co.uk>
Reviewed-by: Marty Connor <mdc@etherboot.org>
Signed-off-by: Guo-Fu Tseng <cooldavid@cooldavid.org>
Modified-by: Michael Brown <mcb30@ipxe.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>