isci: fix fragile/conditional isci_host lookups

A domain_device can always reference back to ->lldd_ha unlike local lldd
structures.  Fix up cases where the driver uses local objects to look up the
isci_host.  This also changes the calling conventions of some routines to
expect a valid isci_host parameter rather than re-lookup the pointer on entry.

Incidentally cleans up some macros that are longer to type than the open-coded
equivalent:
  isci_host_from_sas_ha
  isci_dev_from_domain_dev

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/scsi/isci/phy.c b/drivers/scsi/isci/phy.c
index decc0c0..9e081a4 100644
--- a/drivers/scsi/isci/phy.c
+++ b/drivers/scsi/isci/phy.c
@@ -163,7 +163,7 @@
 			return -ENODEV;
 
 		/* Perform the port reset. */
-		ret = isci_port_perform_hard_reset(iport, iphy);
+		ret = isci_port_perform_hard_reset(ihost, iport, iphy);
 
 		break;