msm: mdss: remove hdmi audio sysfs node

Use audio codec callback to replace the existing sysfs
node which has permission issues. The usage is the same
as previous sysfs node as the input parameters are not
changed.  There are 3 different flags could be passed
in: SET_ENABLE, ENABLE, and CONNECT.

CRs-Fixed: 2010135
Change-Id: Id526bd8a3d750f8da108bc42b1e3e8f680950f3b
Signed-off-by: Ray Zhang <rayz@codeaurora.org>