[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type

These enums have been separate since the dawn of SAS, mainly because the
latter is a procotol only enum and the former includes additional state
for libsas.  The dichotomy causes endless confusion about which one you
should use where and leads to pointless warnings like this:

drivers/scsi/mvsas/mv_sas.c: In function 'mvs_update_phyinfo':
drivers/scsi/mvsas/mv_sas.c:1162:34: warning: comparison between 'enum sas_device_type' and 'enum sas_dev_type' [-Wenum-compare]

Fix by eliminating one of them.  The one kept is effectively the sas.h
one, but call it sas_device_type and make sure the enums are all
properly namespaced with the SAS_ prefix.

Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/sas.h b/include/scsi/sas.h
index be3eb0b..0d2607d 100644
--- a/include/scsi/sas.h
+++ b/include/scsi/sas.h
@@ -90,16 +90,18 @@
 };
 
 /* See sas_discover.c if you plan on changing these */
-enum sas_dev_type {
-	NO_DEVICE   = 0,	  /* protocol */
-	SAS_END_DEV = 1,	  /* protocol */
-	EDGE_DEV    = 2,	  /* protocol */
-	FANOUT_DEV  = 3,	  /* protocol */
-	SAS_HA      = 4,
-	SATA_DEV    = 5,
-	SATA_PM     = 7,
-	SATA_PM_PORT= 8,
-	SATA_PENDING  = 9,
+enum sas_device_type {
+	/* these are SAS protocol defined (attached device type field) */
+	SAS_PHY_UNUSED = 0,
+	SAS_END_DEVICE = 1,
+	SAS_EDGE_EXPANDER_DEVICE = 2,
+	SAS_FANOUT_EXPANDER_DEVICE = 3,
+	/* these are internal to libsas */
+	SAS_HA = 4,
+	SAS_SATA_DEV = 5,
+	SAS_SATA_PM = 7,
+	SAS_SATA_PM_PORT = 8,
+	SAS_SATA_PENDING = 9,
 };
 
 enum sas_protocol {