[Genlist] Applied Upstream patch r62778.

[Genlist] Applied Upstream patch r62778.

From: Jaehwan Kim <jae.hwan.kim@samsung.com>
Subject: [E-devel] [Patch] elm_genlist_clear

When items are added right after genlist clear, genlist is scrolled to the previous position.
If all item is deleted, the scroller have to locate 0, 0.
But scroller has wanted position to remembers the scrolled location.
So even if all item is deleted, it locate previous position.
Then I added elm_smart_scroller_child_region_show(wd->scr, 0, 0, 0, 0)
at the end of the elm_genlist_clear.

git-svn-id: https://svn.enlightenment.org/svn/e/trunk/elementary@62778 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33