[BNX2X]: Correct RX filtering and MC configuration

The configuration of RX filtering needed the following corrections:

Drop flags need to be set per Rx queue.

Have to tell the microcode to collect drop stats, and properly wait
for them to complete when going down.

Sometimes we failed to detect proper completion due to a logical error
in the wait loop.

Signed-off-by: Eliezer Tamir <eliezert@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>