Input: ALPS - add support for protocol versions 3 and 4
This patch adds support for two ALPS touchpad protocols not
supported currently by the driver, which I am arbitrarily naming
version 3 and version 4. Support is single-touch only at this time,
although both protocols are capable of limited multitouch support.
Thanks to Andrew Skalski, who did the initial reverse-engineering
of the v3 protocol.