drm/amd/powerplay: disable FFC.

SMC need use VBI signal for MCLK switching
Send 2 x frame time as vbi timeout

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
3 files changed