[SCSI] mpt fusion: rewrite taskmgmt request and completion routines

1.)	 rewrite taskmanagement request and completion routines, making them
single threaded and using the generic MPT_MGMT struct, deleting
mptscsih_TMHandler, replacing with single request TM handler
mptscsih_IssueTaskMgmt, and killing the watchdog timer functions.
2.) cleanup ioc_reset callback handlers, introducing wrappers for
synchronizing error recovery (mpt_set_taskmgmt_in_progress_flag,
mpt_clear_taskmgmt_in_progress_flag), as the fusion firmware only handles
one task management request at a time

Signed-off-by: Kashyap Desai <kadesai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>