Add ".so" shared objects to .gitignore

For intel_stubs.so
Signed-off-by: Rhys Kidd <rhyskidd@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

.gitignore

 bin
 run
+*.so