- Add new aux_channel_type
- Changed port_index to instance in dmub_cmd_dp_aux_control_data
- Change aux_return_code_type to sync up with driver
- param for ramping abm based on backlight level

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>