[SCSI] qla2xxx: defer topology discovery to DPC thread during initialization.

Modify intialization semantics:

- perform basic hardware configuration only (as usual)
  - allocate resources
  - load and execute firmware

- defer link (transport) negotiations to the DPC thread
  - again the code in qla2x00_initialize_adapter() to stall probe()
    completion was needed for legacy-style scanning.
  - DPC thread stalls until probe() complete.

- before probe() completes, set DPC flags to perform loop-resync logic
  (similar to what's done during cable-insertion/removal).

Benefits: user does not have to wait 20+ seconds in case the FC cable
is unplugged during driver load, code consolidation (removal of
redundant link negotiation logic during initialize_adaoter()), and
finilly, the driver no longer needs to defer the fc_remote_port_add()
calls to hold off lun-scanning prior to returning from the probe()
function.

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