HID: support for logitech cordless desktop LX500 special mapping

This keyboard has wireless mouse which has left, middle, right buttons and
2-dimensional scrolling wheel.  Unfornetuly, this wheel reports side scrolling
events and 11 or 12 button events at the same time.

I've wrote a patch to fix this mapping.  I'm not sure if this mapping is proper
for buttons, because , for example, there is no entry for "burn cd" in input.h.

The patch also supress 11 and 12 button events from mouse when you scroll the
wheel left and right.  With this patch, only side scrolling events are
reported.  (This mouse has only 4 buttons and 2D wheel. There is no such
buttons like 11 and 12.)

Signed-off-by: Jiri Kosina <jkosina@suse.cz>