CVE-2024-26661

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Add NULL test for 'timing generator' in 'dcn21_set_pipe()'

In "u32 otg_inst = pipe_ctx->stream_res.tg->inst;"
pipe_ctx->stream_res.tg could be NULL, it is relying on the caller to
ensure the tg is not NULL.