Mark regs.usprivacy deprecated

[dmdabbs]

"US Privacy" is deprecated, as of 1 Jan 2024.
That signal is still "active" (or not deprecated) in the regs section.

Suggest tagging it as DEPRECATED on the way to removal.

[bmayd]

Seems like a good idea; the associated section 7.5 - Regs Resources needs to be updated as well.