qlcnic: Secondary unicast MAC address support.

Add support for configuring secondary unicast address which
will use existing HW filters to store all the unicast MAC
addresses and prevent device going into promiscuous mode.

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