Add piglit_set_timeout for tests that might hang.

Signed-off-by: Jamey Sharp <jamey@minilop.net>
glx_oml_sync_control: Implemented timing test
glx-oml-sync-control: Added repeat-swapbuffer test

This test checks that when swapbuffers is called multiple times
without waitSBC that the SBC is not incremented more often than
the MSC.
glx_oml_sync_control: Added timeouts to tests using SwapBuffersMsc