net/bnx2x: fix FW command timeout during stop

net/bnx2x: fix FW command timeout during stop

This patch fixes firmware command timeout error seen during device stop
while stopping queues. It patially reverts an earlier preventive change
commit 91b7e432bcef ("net/bnx2x: disable fast path interrupts") to now
enable fast path interrupts.

The original issue of performance degradation is not observed anymore,
with or without the fix.

Fixes: 91b7e432bcef ("net/bnx2x: disable fast path interrupts")
Cc: stable@dpdk.org
Signed-off-by: Rasesh Mody <rasesh.mody@cavium.com>