[SCSI] libsas: use ->set_dmamode to notify lldds of NCQ parameters

sas_discover_sata() notifies lldds of sata devices twice.  Once to allow
the 'identify' to be sent, and a second time to allow aic94xx (the only
libsas driver that cares about sata_dev.identify) to setup NCQ
parameters before the device becomes known to the midlayer.  Replace
this double notification and intervening 'identify' with an explicit
->lldd_ata_set_dmamode notification.  With this change all ata internal
commands are issued by libata, so we no longer need sas_issue_ata_cmd().

The data from the identify command only needs to be cached in one
location so ata_device.id replaces domain_device.sata_dev.identify.

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

drivers/scsi/aic94xx/aic94xx_init.c

@@ -1009,6 +1009,8 @@ static struct sas_domain_function_template aic94xx_transport_functions = {
 	.lldd_clear_nexus_ha	= asd_clear_nexus_ha,
 
 	.lldd_control_phy	= asd_control_phy,
+
+	.lldd_ata_set_dmamode	= asd_set_dmamode,
 };
 
 static const struct pci_device_id aic94xx_pci_table[] __devinitdata = {