MAINTAINERS: Add RTLA entry

Add an RTLA entry in the MAINTAINERS file with Steven Rostedt and
myself as maintainers.

Link: https://lkml.kernel.org/r/50d8870522580905a1c7f3e6fb611a700f632af1.1643994005.git.bristot@kernel.org



Cc: Joe Perches <joe@perches.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>