drm/amd/display: Refactor DML21 Initialization and Configuration

[Why & How]
- Consolidated the initialization of DML21 parameters into a single
function `dml21_populate_dml_init_params` to streamline the process
and improve code readability.
- Updated the function signatures in the header files to reflect changes
in parameter passing for DML context.
- Removed redundant debug option handling and integrated it into the new
configuration population function.
- Adjusted the DML21 initialization logic in the wrapper to accommodate
the new structure, ensuring compatibility with different DCN versions.
- Enhanced the handling of clock parameters and bounding box configurations
from various sources, including hardware defaults and software policies.
- Improved the clarity of the code by renaming functions and variables for
better understanding of their purposes.

Reviewed-by: Austin Zheng <austin.zheng@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Wenjing Liu