bnx2x: Link-flap avoidance in switch dependent mode

As part of the previous unload flow, probed devices will reset the chip
in order to clean the remains of the UNDI driver.
As a result, it's possible for the FW to toggle the link.

This toggling can prove fatal, as long periods without link can cause the
filesystem mount to fail as the storage protocol timeouts. This has been
observed against particular switches with long link re-establishment time.

This patch informs FW during the reset period that the link should not
be toggled - the FW will keep it alive until some interface will load and claim
the link as its own.

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
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>