There was a registration mechanism to listen to HID outputs with a
specific HID id.
However, the UHID gamepad processor handles several ids, so it cannot
work. We could complexify the registration mechanism, but instead,
directly dispatch to the expected processor based on the UHID id.
Concretely, instead of passing a sc_uhid_devices instance to construct a
sc_keyboard_uhid, so that it can register itself, construct the
sc_uhid_devices with all the UHID instances (currently only
sc_keyboard_uhid) so that it can dispatch HID outputs directly.
PR #5270 <https://github.com/Genymobile/scrcpy/pull/5270>