drm/amd/display: configurable aux timeout support

[Description]
1-add configurable timeout support to aux engine.
2-add timeout support field to dc_caps
3-add reg_key to override extended timeout support

Signed-off-by: abdoulaye berthe <abdoulaye.berthe@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>