elm/hoversel: Recalculate items before box calculate.

Summary:
After the item is packed into the box,
the min of the item can be initialized with content_set working.
content_set calls parent_set and checks the theme when calling parent_set.
At that time, if theme is changed in the parent of layout using hoversel,
call theme_apply(efl_ui_layout) to make min value 0, 0.
This patch can avoid it.

Test Plan: N/A

Reviewers: YOhoho, Hermet, woohyun, zmike, Jaehyun_Cho

Reviewed By: Jaehyun_Cho

Subscribers: cedric, reviewers, committers

Tags: efl

Differential Revision: https://phab.enlightenment.org/D10712