HID: fix Logitech WingMan Formula GP joined axes

The Logitech WingMan Formula GP by default presents a combined
accelerate/brake axis, so this patch assigns it to hid-logitech in order to
benefit from the axis-splitting logic in lg4ff. There is also a fixed
report descriptor for the resulting report.

Signed-off-by: Jarrad Whitaker <jarrad.whitaker@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>