ata: libata-scsi: Use ata_ncq_supported in ata_scsi_dev_config()

In ata_scsi_dev_config(), instead of hard-coding the test to check if
an ATA device supports NCQ by looking at the ATA_DFLAG_NCQ flag, use
ata_ncq_supported().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>