drm-misc for 4.12:

Core:
- Removed some fb subsampling dimension checks from core (Ville)
- Some MST slot cleanup (Dhinakaran)
- Extracted drm_debugfs.h & drm_ioctl.h from drmP.h (Daniel)
- Added drm_atomic_helper_shutdown() to compliment suspend/resume counterparts
  (Daniel)
- Pipe context through legacy modeset to remove legacy_backoff nasties (Daniel)
- Cleanups around vblank as well as allowing lockless counter reads (Chris W.)
- VGA Switcheroo added to MAINTAINERS with Lukas Wunner as reviewer (Lukas)

Drivers:
- Enhancements to rockchip driver probe (Jeffy) and dsi (Chris Z.)
- Thunderbolt external GPU awareness added (Lukas)