be2net: call ENABLE_VF cmd for Skyhawk-R too

This cmd needs to be sent to FW when enabling VFs (currently used only
for Lancer.) Also, avoid calling the cmd when driver loads and finds that
VFs are already enabled from a previous load.

Signed-off-by: Vasundhara Volam <vasundhara.volam@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>