bnx2x: Fix SFP+ misconfiguration in iSCSI boot scenario

Fix a problem in which iSCSI-boot installation fails when switching SFP+ boot
port and moving the SFP+ module prior to boot. The SFP+ insertion triggers an
interrupt which configures the SFP+ module wrongly before interface is loaded.

Signed-off-by: Yaniv Rosner <yanivr@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>