Add pointer and buttonpad properties for v4 hardware.

Also, Jachiet reported that on Asus UX31, right button has no effect.
It turns out v4 has only one button, the right-button effect is
implemented with software when Windows driver is installed, or in
firmware when touchpad is in relative mode. So remove BTN_RIGHT
while at it.
Reported-by: NJachiet Louis <louis@jachiet.com>
Signed-off-by: NJJ Ding <jj_ding@emc.com.tw>
Reviewed-by: NChase Douglas <chase.douglas@canonical.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>