Input: appletouch - improve powersaving for Geyser3 devices

The appletouch geyser3 devices found in the Intel Macs (and possibly
some later PPC ones?) send a constant stream of packets after the first
touch. This results in the kernel waking up around once every couple of
milliseconds to process them, making it almost impossible to spend any
significant amount of time in C3 state on a dynamic HZ kernel. Sending
the mode initialization code makes the device shut up until it's touched
again. This patch does so after receiving 10 packets with no interesting
content.

Signed-off-by: Soeren Sonnenburg <kernel@nn7.de>
Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>