contrib: change dxva2api.h checksum

I added a workaround for mingw64
(cherry picked from commit 8fd4111acb17d4d887f163badd25c92a9465a51e)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

contrib/src/directx/SHA512SUMS

 03620b89ed8f9e9e339be9f7024d1f9a71468cba0ac2389eabd68ed1f1aa0a2d6e67c42c93f9a91eb43cf06964112dc9942ae49f8b532ff5c69db53d6b03edf8  directx-oss.tar.bz2
-e62868480379fbb7bc7a433836c6884d51e35ca2d903b9b1f0944250a9d87814be087237240ce84e6d173ea84faed5ea834f2b38800e5ac2c2d8365726defb6a  dxva2api.h
+042a492aa55c4481552a27b8042e62b027edaf317d217e5c93f2c1aa952bfefca93088c22484d3a2b4d111df57ceb8024fe3922f67fc1a6fa6434fb6630b72be  dxva2api.h