qlcnic: add support for FDB netdevice ops.

Providing communication channel between KVM and e-Switch so that it
can be informed when hypervisor configures a MAC address and VLAN.

qlcnic_mac_learn module param usage will be changed to:
	0 = MAC learning is disable
	1 = Driver learning is enable
	2 = FDB learning is enable

Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>