msm: mdss: hdmi: modify min_enc_level logic

Now display HAL will call hdcp library's min_enc_level sysfs
entry instead of hdcp2p2's min_enc_level sysfs entry.
This will make sure hdcp lib to have better control on
content type transmission.
hdcp lib will notify hdcp2p2 driver regarding new encryption
level.

Change-Id: Ibf3c51f7f8ad7db2520a434308361c31379c4948
Signed-off-by: Narender Ankam <nankam@codeaurora.org>
Signed-off-by: Ramendra Kumar <ramendra@codeaurora.org>