rtla: Documentation: fix email addresses

Correct lkml@vger to linux-kernel@vger.
Add linux-trace-devel since that is what is in the MAINTAINERS file.

Fixes: d40d48e1

 ("rtla: Add Documentation")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>