msm: BA: Create Bridge Abstraction (BA)

Create bridge abstraction driver to provide a framework that can be
used to abstract different types of bridge chips under a common API.
The framework also allows multiple drivers to control different
functional aspects of a bridge chip.
The bridge abstraction driver is limited to bridge chips that deal
with converting audio/video data from one protocol to a different one.

Change-Id: Ib42365fb41afda8029f4f6e9b1ec27549d885659
Signed-off-by: Domi Papoi <dpapoi@codeaurora.org>