[SCSI] qla2xxx: Workaround D3 power-management issues.

Early ISP2432 parts have a known hardware issue when coming
out of a D3 hot state.  This issue can result in a hung PCIe
link.  Recent firmwares contain a workaround whereby the
stop-firmware mailbox command prevents the ISP from entering
the D3 hot state.

In order to ensure that the workaround succeeded the driver
must verify that the stop-firmware mailbox command completes
successfully.  In the event of a failure, the driver
attempts a shutdown-retry after resetting the ISP and
re-executing firmware.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>