cxgb4: rework queue config and MSI-X allocation

Simplify queue configuration and MSI-X allocation logic. Use a single
MSI-X information table for both NIC and ULDs. Remove hard-coded
MSI-X indices for firmware event queue and non data interrupts.
Instead, use the MSI-X bitmap to obtain a free MSI-X index
dynamically. Save each Rxq's index into the MSI-X information table,
within the Rxq structures themselves, for easier cleanup.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>