drm/amd/display: VBIOS can't be light up HDMI when restart system

drm/amd/display: VBIOS can't be light up HDMI when restart system

[Why]
VBIOS will not post pixel rate > 340MHz.
If driver set pixel rate > 340MHz and do restart bottom, VBIOS can't
post HDMI monitor due to monitor is stay in HDMI2.0 state.

[How]
Program Scrambling_Enable and TMDS_Bit_Clock_Ratio when disable stream.

Signed-off-by: Paul Hsieh <paul.hsieh@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>