msm: mdss: Prevent HDMI panels from doing AD checks

Assertive display is meant only for primary display, however the AD
checks are being done on the HDMI frame buffer and its mixers. Adding
a check for HDMI panel type will prevent edge case errors when doing
AD checks.

Change-Id: Iffdec9fcf479f24e9407d6508517fb4103b1e977
Signed-off-by: Benet Clark <benetc@codeaurora.org>