HID: wiimote: parse reduced status reports

It turns out the Wii accepts any status reports from clients reduced to
"BB BB" key data only, as long as the report actually includes key data at
the first two bytes.

The official devices don't send these reduced reports, but of course, 3rd
party devices make great use of this feature.

Hence, add parsers for these reduced reports for every matching report.
Also change the logic how we find handlers. There is no reason to call
multiple handlers on a single report, but instead find the best handler
and call it only once.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>