Added initial code for VP9 support. (#442)

* * rocDecode/VP9: Initial code for VP9.
 - Added structures for VA-API.
 - Added defines for uncompressed header and parsing functions.

* * rocDecode/VP9: Added decode frame call to VA-API.

* * rocDecode/VP9: Added new sequence notification function.

* * rocDecode/VP9: Intra decode started to work.

* * rocDecode/VP9: Minor changes based on review comments.

---------

Co-authored-by: Kiriti Gowda <kiritigowda@gmail.com>

[ROCm/rocdecode commit: 3eb6bc2192]

projects/rocdecode/src/parser/rocparser_api.cpp

@@ -36,6 +36,7 @@ rocDecCreateVideoParser(RocdecVideoParser *parser_handle, RocdecParserParams *pa
 
     if (parser_params->codec_type != rocDecVideoCodec_HEVC &&
         parser_params->codec_type != rocDecVideoCodec_AVC &&
+        parser_params->codec_type != rocDecVideoCodec_VP9 &&
         parser_params->codec_type != rocDecVideoCodec_AV1) {
         ERR("The current version of rocDecode officially supports only the H.265 (HEVC), H.264 (AVC) and AV1 codecs.");
         return ROCDEC_NOT_IMPLEMENTED;