be2net: pad skb to meet minimum TX pkt size in BE3

On BE3 chips in SRIOV configs, the TX path stalls when a packet less
than 32B is received from the host. A workaround to pad such packets
already exists for the Skyhawk and Lancer chips. Use the same workaround
for BE3 chips too.

Signed-off-by: Suresh Reddy <suresh.reddy@avagotech.com>
Signed-off-by: Sathya Perla <sathya.perla@avagotech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>