efl_ui_widget: fix regression of legacy object creation

efl_ui_widget: fix regression of legacy object creation

It was allowed to use non widget object as a parent of Efl.Ui.Image_Legacy.
Please refer to following error messages.

eo<896> ../src/lib/eo/eo.c:947 _efl_add_internal_start_do() in ../src/lib/elementary/efl_ui_image.c:2303: Object of class 'Efl.Ui.Image_Legacy' - Error while constructing object
eo<896> ../src/lib/eo/eo.c:579 _efl_object_call_resolve() in src/lib/elementary/efl_ui_widget.eo.c:268: func 'efl_ui_widget_sub_object_add' (579) could not be resolved for class 'Evas.Canvas'.

It seems that application is using Evas.Canvas to add Efl.Ui.Image_Legacy.
We could not see some images after commit aa2d94f.

aa2d94f efl_ui_widget: add a place to share data
This patch makes the commit aa2d94f work only for non legacy object.

Reason of tizen only: D9713
*tizen-fix

Change-Id: I1b96ddc6e79af3c4100f5034741b9280f17c3c6b