test: drop the sleep_ms argument

This forces events for every ~10ms now. If we want a slower movement, we need
more steps - just like a real touchpad does it.

Cocinelle spatch files were variants of:
	@@
	expression A, B, C, D, E, F, G, H, I, J, K;
	@@

	- litest_touch_move_two_touches(A, B, C, D, E, F, G, H, I)
	+ litest_touch_move_two_touches(A, B, C, D, E, F, G, H)

The only test that needed a real fix was touchpad_no_palm_detect_2fg_scroll,
it used 12ms before, now it's using 10ms so on the bcm5974 touchpad the second
finger was a speed-thumb. Increasing the events and thus slowing down the
pointer means it's a normal finger and the test succeeds again.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>