ixgbe: Fix for RAR0 not being set to default MAC addr

commit c9f53e63

 ("ixgbe: Refactor MAC address configuration code")
introduced code that doesn't set HW register RAR0 to default mac address
but FF:FF:FF:FF:FF:FF. Due to this, ixgbe HW discards all incoming packets
that doesn't have destination mac address equals to FF:FF:FF:FF:FF:FF.

This commit sets RAR0 correctly to default HW mac address.

Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Tested-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>