targets/xvmc: limit the amount of exported symbols
In the presence of LLVM the final library exports every symbol from
the llvm namespace. Resolve this by using a version script (w/o the
version/name tag).
Considering that there are only ~25 symbols, explicitly list them
to minimize the chances of rogue symbols sneaking in.
Drop the *winsys_create functions as they were only meant for
gl-vdpau interop.
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>