Update the copyright notice with the current year and add a note
about values for controlling the Dualshock 4 reporting rate.

Processing reports at the default full rate of 1000hz can be too
demanding for some low-power embedded processors so noting
alternate values for people working with this hardware can be useful.

Thanks to Rostislav Pehlivanov for finding these values.
Signed-off-by: Frank Praznik <frank.praznik@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>