i9300: Initial bringup - making it build in Omni build env.

It boots up properly with most of the functionallity.
What's missing currently is GPS, TvOut, FM and BT.

PS4 - added proper custom config with Omni specific inherits.
It brunches now!

PS5 - preparation for omni vendor config, it won't build just yet.

PS6 - Fixed AndroidProducts.mk - it should build as omni now.

Change-Id: Ic5c31796cbfb73470caf678b199ac1329e30c5b7