IB/mlx4: Separate tunnel and wire bufs parameters

Using CX-3 in virtualized mode, MAD packets are proxied through the PF
driver. The feed is N tunnel QPs, and what is received from the VFs is
multiplexed out on the wire QP. Since this is a many-to-one scenario, it
is better to have separate initialization parameters for the two usages.

The number of wire and tunnel bufs are yanked up to 2K and 512
respectively. With this set of parameters, a system consisting of eight
physical servers, each with eight VMs and 14 I/O servers (BM), can run
switch fail-over without seeing:

mlx4_ib_demux_mad: failed sending GSI to slave 3 via tunnel qp (-11)

or

mlx4_ib_multiplex_mad: failed sending GSI to wire on behalf of slave 2 (-11)

Fixes: 3cf69cc8 ("IB/mlx4: Add CM paravirtualization")
Link: https://lore.kernel.org/r/20200803061941.1139994-4-haakon.bugge@oracle.com


Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>