MAINTAINERS: Add Runtime Verification (RV) entry

Add a Runtime Verification (RV) entry in the MAINTAINERS file
with Steven Rostedt and myself as maintainers.

Link: https://lkml.kernel.org/r/b24c13553b6947a8da16d884ca464e4233eb8fb7.1661268579.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>