qlge: Add support for using alternate MAC address.

Extract either manufacturer or Bladecenter Open Fabric
Manager (BOFM) MAC address.  BOFM may indicate an
alternate MAC address.  This patch honors that request
by extracting the MAC address from a different
flash location if a flag is set.

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>