[packages] gstreamer: update grammar.y to build with bison 3

In gstreamer's gst/parse/grammar.y, YYLEX_PARAM is no longer supported in bison
3. Replace YYLEX_PARAM with %lex-param.

Signed-off-by John Vogel <jvogel4@stny.rr.com>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@39182 3c298f89-4303-0410-b956-a3cf2f4a3e73