CVE-2026-74732 drm/amd/display: Check for tg ops in dce110_set_avmute

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Check for tg ops in dce110setavmute Some older DCE timing generators do not implement istgenabled in their ops table. Calling it unconditionally when waiting for AV mute frames causes a NULL pointer dereference o...