input: keyboard: switch legacy handlers to new core

input: keyboard: switch legacy handlers to new core

legacy kbd event handlers are registered in the new core,
so they receive events from the new input core code.
keycode -> scancode translation needed here.

legacy kbd_put_keycode() sends events to the new core.
scancode -> keycode translation needed here.

So with this patch the new input core is fully functional
for keyboard events.  New + legacy interfaces can be mixed
in any way.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>