drm/amd/display: Add Validate BW for USB4 Links

[WHY]
To validate the BW used for DPIAs per HostRouter

[HOW]
Add the Validate function in C source file

Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Mustapha Ghaddar <mghaddar@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>