bnx2x: Fix Maximum CoS estimation for VFs

bnx2x VFs do not support Multi-CoS; Current implementation
erroneously sets the VFs maximal number of CoS to be > 1.

This will cause the driver to call alloc_etherdev_mqs() with
a number of queues it cannot possibly support and reflects
in 'odd' driver prints.

Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Ariel Elior <ariele@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>