How do you enable the app-context-dependent touch bar for Photoshop on the new 2016 rmbp
You run Photoshop CC 2017 Version 18.0.1?

From the release note: 


  Use the Touch Bar with Photoshop - Photoshop now supports Touch Bar,
  the multitouch display at the top of the new MacBook Pro keyboard;
  Touch Bar support in Photoshop is currently a technology preview
  feature


Adobe said it is an experimental feature. It could be that this functions is not turned on automatically. 

You can turn it on here: Preferences > Technology Previews > Enable Touch Bar