scsi: sas: provide stub implementation for scsi_is_sas_rphy

Provide a stub implementation for scsi_is_sas_rphy for kernel
configurations which do not have CONFIG_SCSI_SAS_ATTRS defined.
Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: James Bottomley <jejb@linux.vnet.ibm.com>
Reviewed-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

include/scsi/scsi_transport_sas.h

@@ -15,8 +15,14 @@ static inline int is_sas_attached(struct scsi_device *sdev)
 {
 	return 0;
 }
+
+static inline int scsi_is_sas_rphy(const struct device *sdev)
+{
+	return 0;
+}
 #else
 extern int is_sas_attached(struct scsi_device *sdev);
+extern int scsi_is_sas_rphy(const struct device *);
 #endif
 
 static inline int sas_protocol_ata(enum sas_protocol proto)
@@ -202,7 +208,6 @@ extern int sas_rphy_add(struct sas_rphy *);
 extern void sas_rphy_remove(struct sas_rphy *);
 extern void sas_rphy_delete(struct sas_rphy *);
 extern void sas_rphy_unlink(struct sas_rphy *);
-extern int scsi_is_sas_rphy(const struct device *);
 
 struct sas_port *sas_port_alloc(struct device *, int);
 struct sas_port *sas_port_alloc_num(struct device *);