net/vmxnet3: support version 6

net/vmxnet3: support version 6

VMXNET3 version 6 supports some new features, including but not limited to:
 - Increased maximum MTU up to 9190
 - Increased maximum number of Rx and Tx queues
 - Removes power-of-two limitations on queue sizes
 - Extended interrupt structures (required for additional queues)

Tested, using testpmd, for different hardware versions on ESXi 7.0
Update 2.

Signed-off-by: Pankaj Gupta <pagupta@vmware.com>
Reviewed-by: Jochen Behrens <jbehrens@vmware.com>