ideapad: add event for Novo key

Novo key is the Lenovo define key on every ideapads, which has two
definition. Long press and short click. Driver will report
KEY_PROG1 on short click and KEY_PROG2 when long press.

On pre-install OS for ideapads there are application waiting for
the event and there is no such application for Linux yet, so I
think to report KEY_PROG is fine in anyway.

Also change the scancode from hex to decimal because they are
related to vpc bit in notify function which is in decimal.

Signed-off-by: Ike Panhc <ike.pan@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>