[SCSI] libsas: improve debug statements

It's difficult to determine which domain_device is triggering error recovery,
so convert messages like:

  sas: ex 5001b4da000e703f phy08:T attached: 5001b4da000e7028
  sas: ex 5001b4da000e703f phy09:T attached: 5001b4da000e7029
  ...
  ata7: sas eh calling libata port error handler
  ata8: sas eh calling libata port error handler

...into:

  sas: ex 5001517e85cfefff phy05:T:9 attached: 5001517e85cfefe5 (stp)
  sas: ex 5001517e3b0af0bf phy11:T:8 attached: 5001517e3b0af0ab (stp)
  ...
  sas: ata7: end_device-21:1: dev error handler
  sas: ata8: end_device-20:0:5: dev error handler

which shows attached link rate, device type, and associates a
domain_device with its ata_port id to correlate messages emitted from
libata-eh.

As Doug notes, we can also take the opportunity to clarify expander phy
routing capabilities.

[dgilbert@interlog.com: clarify table2table with 'U']
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>