Summary:
correct group name of segmentcontrol for API docs consistency.
Elm_SegmentControl -> Elm_Segment_Control
Test Plan: N/A
Reviewers: Jaehyun_Cho
Reviewed By: Jaehyun_Cho
Subscribers: cedric, #reviewers, #committers
Tags: #efl
Differential Revision: https://phab.enlightenment.org/D7087