tracing: Update MAINTAINERS to reflect new tracing git repo

The tracing git repo will no longer be housed in my personal git repo,
but instead live in trace/linux-trace.git.

Update the MAINTAINERS file appropriately.

Link: https://lkml.kernel.org/r/20221006144439.282193367@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>