qed: Use VF-queue feature

Driver sets several restrictions about the number of supported VFs
according to available HW/FW resources.
This creates a problem as there are constellations which can't be
supported [as limitation don't accurately describe the resources],
as well as holes where enabling IOV would fail due to supposed
lack of resources.

This introduces a new interal feature - vf-queues, which would
be used to lift some of the restriction and accurately enumerate
the queues that can be used by a given PF's VFs.

Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>