drm/amd/display: Fix hang/underflow when transitioning to ODM4:1

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix hang/underflow when transitioning to ODM4:1 [Why] Under some circumstances, disabling an OPTC and attempting to reclaim its OPP(s) for a different OPTC could cause a hang/underflow due to OPPs not being properly disconnected from the disabled OPTC. [How] Ensure that all OPPs are unassigned from an OPTC when it gets disabled.