telephony: add SamsungExynos4RIL class

Forward ported from CM10 including contributions from:
Andrew Dodd<atd7@cornell.edu>
Daniel Bateman <jetison.24@gmail.com>
Daniel Hillenbrand <codeworkx@cyanogenmod.org>
Ethan Chen <intervigil@gmail.com>
Lee Chu <lee.lc.chu@gmail.com>
Mike Kasick <mike@kasick.org>

Change-Id: Ibc33a866a02a88b346ae30aa6f09a398edfc79c1