Input: ALPS - clean up TrackStick handling for SS5 hardware

For consistency and clarity, the input_report_*() functions should be
called by alps_process_packet_ss4_v2() instead of by alps_decode_ss4_v2().

Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Paul Donohue <linux-kernel@PaulSD.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>