GitLab

- Disabled HPD filter and used HPD software timer instead
- Allows DM to disable HPD filtering
Signed-off-by: John Barberiz <jbarberi@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>