Add support for setting and clearing the CDR bits
Add support for setting and clearing the CDR bits

Summary: This allows one to set and clear the CDR bits. I also added extra visibility into whether CDR is supported on the device (previously you had to do your own bit manipulations on the extended id bit)

Reviewed By: aeckert

Differential Revision: D3629366

fbshipit-source-id: 1003393f6e53eb49d3747d342a99bf81d2080844

peterlei/fboss,peterlei/fboss,peterlei/fboss,peterlei/fboss