vmxnet3: update to version 3

With all vmxnet3 version 3 changes incorporated in the vmxnet3 driver,
the driver can configure emulation to run at vmxnet3 version 3, provided
the emulation advertises support for version 3.

Signed-off-by: Shrikrishna Khare <skhare@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>