DRM: SDE: Update the hdmi bridge to handle HPD clock

For non-pluggable display, it should not enable HPD.  Instead, the
bridge should handle all the clocks for HDMI.  Also the scrambler
should be activated after the HDMI has power on the clock.

Change-Id: I9162a49b8f314de4d30b0d82c7867a639ddf05a6
Signed-off-by: Camus Wong <camusw@codeaurora.org>