First slice of 4.13 features:

new uabi:
- extend error state dumping to include non-batch buffers requested by
  userspace (Chris), so that mesa gets more useful error state dumps
- reapply the link status patch, for handlig dp link failures
  (Manasi). This needs updated -modesetting to work correctly.
- Add new _WC cache domain, our assumption that wc can be subsumed by
  the existing cache domains didn't pan out (Chris)

feature work:
- first pile of conversion to atomic properties for connectors
  (Maarten)
- refactor dp link rate handling code and related areas (Jani)
- split engine info into class and runtime stuff (Oscar Mateo)
- more robust wait_for_register code (Chris, Michal Wajdeczko)
- fix rcu issues in the shrinker and simplify locking (Joonas)
- guc/huc for glk (Anusha)
- enable atomic modesetting for vlv/chv (Ville), plus final fixes for
  that