msm: mdss: hdmi: Proper permissions for CEC logical address

Do not give universal access to CEC (Consumer Electronics Control)
sysfs nodes for logical and physical addresses to avoid unauthorized
access.

CRs-Fixed: 547968
Change-Id: I2ba57f050cc92a361586064dfd5e5659ab07c2f7
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>