More 4.11 stuff, holidays edition (i.e. not much):

- docs and cleanups for shared dpll code (Ander)
- some kerneldoc work (Chris)
- fbc by default on gen9+ too, yeah! (Paulo)
- fixes, polish and other small things all over gem code (Chris)
- and a few small things on top

Plus a backmerge, because Dave was enjoying time off too.