[SCSI] target: Convert TASK_ATTR to scsi_tcq.h definitions

This patch converts target core and follwing scsi-misc upstream fabric
modules to use include/scsi/scsi_tcq.h includes for SIMPLE, HEAD_OF_QUEUE
and ORDERED SCSI tasks instead of scsi/libsas.h with TASK_ATTR*

*) tcm_loop: Convert tcm_loop_allocate_core_cmd() + tcm_loop_device_reset() to
   scsi_tcq.h
*) tcm_fc: Convert ft_send_cmd() from FCP_PTA_* to scsi_tcq.h

Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: James Bottomley <jbottomley@parallels.com>