drm/amd/display: Add resource interfaces for get ODM slice rect

[WHY]
We need an unified location to perform ODM slice rect calculation.

[HOW]
Add three interfaces for ODM slice rect/width calucaltion in resource.h

Reviewed-by: George Shen <george.shen@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>