This device sends several buttons in a separate field, which is
wrongly described in the report descriptor. Fix it in the following
way:

- change led usage page to button
- report size 8 count 1 becomes report size 1 count 8
- the button usage range changed to 4-7 (the mouse has three buttons in
  a different field already).
Reported-by: NTomas Hanak <tomas.hanak@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>