msm: mdss: hdmi: remove unnecessary sysfs nodes

Remove dead code of sysfs node implementations which are not being
used to avoid any possible compliance issues related to sysfs nodes.

Change-Id: Ida43cbd04c7b8ec6ad79e9a4c66a7725920ba116
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>