This extends the uhid example client. It properly documents the built-in
report-descriptor an adds explicit report-numbers.
Furthermore, LED output reports are added to utilize the new UHID output
reports of the kernel. Support for 3 basic LEDs is added and a small
report-parser to print debug messages if output reports were received.
To test this, simply write the EV_LED+LED_CAPSL+1 event to the evdev
device-node of the uhid-device and the kernel will forward it to your uhid
Signed-off-by: David Herrmann <firstname.lastname@example.org>
Signed-off-by: Jiri Kosina <email@example.com>