Clean up comments a little bit.
Clean up comments a little bit.

Summary: Mention the platforms we actually support.

Test Plan: It's a comment.

Reviewed By: jasmeetbagga@fb.com

Subscribers: net-systems@

FB internal diff: D1985466

Signature: t1:1985466:1428707246:ab439cbd4f5b54121a7cbdac87b1429d482e4f1d

peterlei/fboss,sonoble/fboss,sonoble/fboss,raphaelamorim/fboss,neuhausler/fboss,biddyweb/fboss,sonoble/fboss,raphaelamorim/fboss,biddyweb/fboss,peterlei/fboss,raphaelamorim/fboss,neuhausler/fboss,peterlei/fboss,biddyweb/fboss,neuhausler/fboss,peterlei/fboss,neuhausler/fboss