isci: combine request flags

Combine three bools into one unsigned long 'flags'.  Doesn't increase the
request size due to packing. (to do: optimize the structure layout).

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --cc drivers/scsi/isci/request.c
Simple merge

diff --cc drivers/scsi/isci/request.h
Simple merge

diff --cc drivers/scsi/isci/task.c
Simple merge