isci: clarify phy to port lookups

While cleaning up the driver it is very tempting to convert scic_sds_get_*
macros to their open coded equivalent.  They are all just pointer dereferences
*except* scic_sds_phy_get_port() which returns NULL if the phy is assigned to
the dummy port.  Clarify this by renaming it to phy_get_non_dummy_port().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/scsi/isci/port_config.c b/drivers/scsi/isci/port_config.c
index 028ffa3..ca76f49 100644
--- a/drivers/scsi/isci/port_config.c
+++ b/drivers/scsi/isci/port_config.c
@@ -353,7 +353,7 @@
 
 		if (configure_phy_mask & (1 << index)) {
 			port_agent->link_up_handler(scic, port_agent,
-						    scic_sds_phy_get_port(sci_phy),
+						    phy_get_non_dummy_port(sci_phy),
 						    sci_phy);
 		}
 	}