Input: elantech - reset touchpad before configuring it

Input: elantech - reset touchpad before configuring it

Acer VH40 has a Fn key toggling the touchpad on and off, but it's
implemented in system firmware, and the EC chip has to receive
reset command to activate this function. Also when this machine
wakes up after resume, psmouse_reset is necessary to bring the
touchpad back on.

Signed-off-by: JJ Ding <jj_ding@emc.com.tw>
Reviewed-by: Chase Douglas <chase.douglas@canonical.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>