protocol: Fix order of wl_pointer, wl_keyboard and wl_touch messages

The "release" message of wl_pointer, wl_keyboard and wl_touch introduced
in version 3 was placed first in the respective interface XML element,
causing wayland-scanner to misbehave and set the version number of the
"release" message to all subsequent messages with no explicitly specified
"since" version.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>