CVE-2025-38205 drm/amd/display: Avoid divide by zero by initializing dummy pitch to 1

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Avoid divide by zero by initializing dummy pitch to 1 Why If the dummy values in populatedummydmlsurfacecfg aren't updated then they can lead to a divide by zero in downstream callers like CalculateVMAndRowBytes...