Merge commit '75d642a9'

* commit '75d642a9':
  vaapi_vp8: Explicitly include libva vp8 decode header
  vaapi_decode: Ignore the profile when not useful
  lavc/vaapi: Add VP8 decode hwaccel
  vp8: Add hwaccel hooks

This merge is a noop as these commits are already under review on the
mailing list. doc/libav-merge.txt is updated to track its progress.
Merged-by: Clément Bœsch <u@pkh.me>

doc/libav-merge.txt

@@ -94,6 +94,7 @@ Stuff that didn't reach the codebase:
   - a853388d2 hevc: change the stride of the MC buffer to be in bytes instead of elements
   - 0cef06df0 checkasm: add HEVC MC tests
   - e7078e842 hevcdsp: add x86 SIMD for MC
+- VAAPI VP8 decode hwaccel (currently under review: http://ffmpeg.org/pipermail/ffmpeg-devel/2017-February/thread.html#207348)
 
 Collateral damage that needs work locally:
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