[SCSI] mpt2sas: Remove code for TASK_SET_FULL from driver.

remove support for MPI2_EVENT_TASK_SET_FULL
This event is obsoleted, so this processing of this event
needs to be removed from the driver.  The controller firmware is going
to handle TASK_SET_FULL, the driver doesn't need to do anything.
Even though we are removing the EVENT handling, the behavour has not
changed between driver versions becuase fimrware will still be handling
queue throttling, and retrying of commands when the target device queues
are full.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>