conformant: find conformant part's owner again if owner is null before sending update...

conformant: find conformant part's owner again if owner is null before sending update of area.

since vkbd's parent can be NULL at the time of vkbd's object is shown, so call
'_conf_part_owner_find' again. the better way I think is exporting related API
so that clipboard and vkbd modules can set its owner directly, or we can use
event mechanism, or checking fetch flag every time we enter the idle (but fetch
flag can be false, careful), and calling '_conf_state_update' at that time.
we need to consider using like this.

Change-Id: I1aacedb28571cc3adf525a9cc1490d0500c8c34d