scsi: target: Add atomic support to target_core_iblock

scsi: target: Add atomic support to target_core_iblock

Make target_core_iblock use the LIO helper function to translate its
block_device atomic settings to LIO settings. If we then get a write
that LIO has indicated is atomic via the SCF_ATOMIC flag, we use the
REQ_ATOMIC flag to tell the block layer to perform an atomic write.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Link: https://patch.msgid.link/20251020103820.2917593-8-john.g.garry@oracle.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>