drm/amd/display: refactor dio link encoder assigning

drm/amd/display: refactor dio link encoder assigning

[WHY]
We would like to have new dio encoder assigning flow.
Which should be aligned with hpo assigning and have
simple logic and data representation.

[HOW}
1. A new config option to enable/disable the new code.
2. Encoder-link mapping is in res_ctx and assigned encoder.
is accessed through pipe_ctx.
3. assign dio encoder when add stream to ctx

Reviewed-by: Jun Lei <jun.lei@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Signed-off-by: Peichen Huang <PeiChen.Huang@amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>