CVE-2026-68104 drm/amdgpu: invoke pm_genpd_remove() before freeing genpd

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: invoke pmgenpdremove before freeing genpd Call pmgenpdremove to unregister from global list prior to releasing acpgenpd memory, and clear the pointer after free. cherry picked from commit...