Pull new experimental media request API from Mauro Carvalho Chehab:
 "A new media request API

  This API is needed to support device drivers that can dynamically
  change their parameters for each new frame. The latest versions of
  Google camera and codec HAL depends on such feature.

  At this stage, it supports only stateless codecs.

  It has been discussed for a long time (at least over the last 3-4
  years), and we finally reached to something that seem to work.

  This series contain both the API and core changes required to support
  it and a new m2m decoder driver (cedrus).

  As the current API is still experimental, the only real driver using
  it (cedrus) was added at staging[1]. We intend to keep it there for a
  while, in order to test the API. Only when we're sure that this API
  works for other cases (like encoders), we'll move this driver out of
  staging and set the API into a stone.

  [1] We added support for the vivid virtual driver (used only for
  testing) to it too, as it makes easier to test the API for the ones
  that don't have the cedrus hardware"

* tag 'media/v4.20-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (53 commits)
  media: dt-bindings: Document the Rockchip VPU bindings
  media: platform: Add Cedrus VPU decoder driver
  media: dt-bindings: media: Document bindings for the Cedrus VPU driver
  media: v4l: Add definition for the Sunxi tiled NV12 format
  media: v4l: Add definitions for MPEG-2 slice format and metadata
  media: videobuf2-core: Rework and rename helper for request buffer count
  media: v4l2-ctrls.c: initialize an error return code with zero
  media: v4l2-compat-ioctl32.c: add missing documentation for a field
  media: media-request: update documentation
  media: media-request: EPERM -> EACCES/EBUSY
  media: v4l2-ctrls: improve media_request_(un)lock_for_update
  media: v4l2-ctrls: use media_request_(un)lock_for_access
  media: media-request: add media_request_(un)lock_for_access
  media: vb2: set reqbufs/create_bufs capabilities
  media: videodev2.h: add new capabilities for buffer types
  media: buffer.rst: only set V4L2_BUF_FLAG_REQUEST_FD for QBUF
  media: v4l2-ctrls: return -EACCES if request wasn't completed
  media: media-request: return -EINVAL for invalid request_fds
  media: vivid: add request support
  media: vivid: add mc
  ...