The previous set hit _some_ sort of limit, but no idea what or why. When
adding one more test, the touchpad test case would reliably fail with a udev
timeout in litest_wait_for_udev(). This only happened in the valgrind case,
the normal run succeeded. Reproduced on three different installations (2 vms
on two different hosts).

Move the tapping tests into a separate binary, this unwedges whatever was
unhappy and sunshine, lollipops and rainbows are distributed generously.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>