Contribs: update dxva2api.h to version 3

Less hacks and tabs in this version
(cherry picked from commit a0f0e09d553708704d00b7145df9c706bd09d380)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/directx/SHA512SUMS

 03620b89ed8f9e9e339be9f7024d1f9a71468cba0ac2389eabd68ed1f1aa0a2d6e67c42c93f9a91eb43cf06964112dc9942ae49f8b532ff5c69db53d6b03edf8  directx-oss.tar.bz2
-042a492aa55c4481552a27b8042e62b027edaf317d217e5c93f2c1aa952bfefca93088c22484d3a2b4d111df57ceb8024fe3922f67fc1a6fa6434fb6630b72be  dxva2api.h
+b3702640c8dc5beeee13413ea4ef897e9842b8c0d07f972007c8aeb282c6f752f1570c2c3b9b81e695c4dc46e2e22d78ac05289e723487c0386cc3e58bce3190  dxva2api.h