eolian_gen: remove reference to elm_entry because it is not installed

eolian_gen: remove reference to elm_entry because it is not installed

Summary:
elm_entry.eo is not installed to system directory like
         "/usr/local/share/eolian/include/elementary-1", and
         eolian_gen tries to refer elm_entry.eo which results in failure.

Test Plan:
Create any eo class file which inherits Efl.Ui.Layout.
           eolian_gen eo_file.eo
           observe eolian_gen finishes

Reviewers: jpeg, herdsman, woohyun, Jaehyun_Cho, cedric

Subscribers: conr2d, id213sin, JongminLee

Differential Revision: https://phab.enlightenment.org/D5760

Change-Id: I00e2e6b082f97e30a3063beba67dc7357a1b1ce4