Add new structure for saving synthesis parameter

Add new structure for saving synthesis parameter

- Requirements:
The app needs to play each utterance with different configuration such
as pitch, speed, volume, or background volume.

- Contents:
This patch adds new structure type for saving synthesis parameter. This
new type will be used for a member of speak_data_s. Through this change,
each speak_data_s can store each synthesis parameter and can make
difference playback utterance using that synthesis parameter.

Change-Id: I58ea401a14d807a1087275dee0dbac7d029a2c91
Signed-off-by: Suyeon Hwang <stom.hwang@samsung.com>