test: split button tests into separate binary
We're again hitting the fork ulimits again (see also 9c2afae1) causing test case failures in the valgrind run of the touchpad test. Split out the touchpad button tests so we don't require special ulimits on test boxes. Signed-off-by:Peter Hutterer <peter.hutterer@who-t.net> Reviewed-by:
Hans de Goede <hdegoede@redhat.com>