Log Message:
dav1d: Update to 0.8.2

0.8.2 is a middle-size update of the 0.8.0 branch:
 - ARM32 optimizations for ipred and itx in 10/12bits,
   completing the 10b/12b work on ARM64 and ARM32
 - Give the post-filters their own threads
 - ARM64: rewrite the wiener functions
 - Speed up coefficient decoding, 0.5%-3% global decoding gain
 - x86 optimizations for CDEF_filter and wiener in 10/12bit
 - x86: rewrite the SGR AVX2 asm
 - x86: improve msac speed on SSE2+ machines
 - ARM32: improve speed of ipred and warp
 - ARM64: improve speed of ipred, cdef_dir, cdef_filter, warp_motion and itx16
 - ARM32/64: improve speed of looprestoration
 - Add seeking, pausing to the player
 - Update the player for rendering of 10b/12b
 - Misc speed improvements and fixes on all platforms
 - Add a xxh3 muxer in the dav1d application