tremor: add patch to export all symbols

Tremor comes with a Version_script file that limits the
list of exported symbols. Without these symbols we can't
build the ivorbisdec GStreamer plug-in (and probably other
application). This commit adds a patch that removes this
limitation and makes all global symbols available.

Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>