scsi: hpsa: remove abort handler

- simplify the driver
- there are a lot of quirky racy conditions not handled
- causes more aborts/resets when the number of commands to be aborted is
  large, such as in multi-path fail-overs.
- has been turned off in our internal driver since 8/31/2015

Reviewed-by: Scott Benesh <scott.benesh@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Reviewed-by: Kevin Barnett <kevin.barnett@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>