firewire: fw-sbp2: implement sysfs ieee1394_id

The attribute /sys/bus/scsi/devices/*:*:*:*/ieee1394_id, as generated by
the old sbp2 driver, is typically used to create persistently named
links in /dev/disk/by-id.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>

drivers/firewire/fw-device.h

@@ -99,6 +99,7 @@ fw_unit(struct device *dev)
 #define CSR_DEPENDENT_INFO	0x14
 #define CSR_MODEL		0x17
 #define CSR_INSTANCE		0x18
+#define CSR_DIRECTORY_ID	0x20
 
 #define SBP2_COMMAND_SET_SPECIFIER	0x38
 #define SBP2_COMMAND_SET		0x39