Because I was looking for a way to do the same thing, came across this page. Nobody had provided a way to do it, so I did some more research and wrote a script. Now the next guy who comes here has a solution.
I wrote this script to output link speed and identify device. It's not pretty, but functional.
#!/bin/sh
for i in `grep -l Gbps /sys/class/ata_link/*/sata_spd`; do
echo Link "${i%/*}" Speed `cat $i`
cat "${i%/*}"/device/dev*/ata_device/dev*/id | perl -nE 's/([0-9a-f]{2})/print chr hex $1/gie' | echo " " Device `strings`
done
see https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-ata