bnxt_en: Call firmware to approve VF MAC address change.

Some hypervisors (e.g. ESX) require the VF MAC address to be forwarded to
the PF for approval.  In Linux PF, the call is not forwarded and the
firmware will simply check and approve the MAC address if the PF has not
previously administered a valid MAC address for this VF.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>