cxgb4vf: Configure queue based on resource and interrupt type

The Queue Set Configuration code was always reserving room for a
Forwarded interrupt Queue even in the cases where we weren't using it.
Figure out how many Ports and Queue Sets we can support. This depends on
knowing our Virtual Function Resources and may be called a second time
if we fall back from MSI-X to MSI Interrupt Mode. This change fixes that
problem.

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>