bnx2x: Ignore bandwidth attention in single function mode

[ Upstream commit 75a110a1783ef8324ffd763b24f4ac268253cbca ]

This is a workaround for FW bug -
MFW generates bandwidth attention in single function mode, which
is only expected to be generated in multi function mode.
This undesired attention in SF mode results in incorrect HW
configuration and resulting into Tx timeout.

Signed-off-by: Shahed Shaikh <Shahed.Shaikh@cavium.com>
Signed-off-by: Ariel Elior <ariel.elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>