msm: cec: Add CEC adapter driver for SDE hardware

This CEC adapter driver using CEC framework provides CEC
support for SDE hardware. CEC is a protocol that provides
high-level control functions between various audiovisual
products. This adapter is the hardware implementation of
CEC protocol, and its major functionality is to send and
to receive CEC messages.

CRs-Fixed: 2041335
Change-Id: I73bc9c63b78d61f5449a37cadcfeda976d5456b0
Signed-off-by: Ray Zhang <rayz@codeaurora.org>