MAINTAINERS: io_uring: Add include/trace/events/io_uring.h

This header file was introduced in commit c826bd7a

 ("io_uring: add
set of tracing events"). It didn't get added to the io_uring
maintainers section. Add this header file to the io_uring maintainers
section.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Link: https://lore.kernel.org/r/20221219164521.2481728-1-ammar.faizi@intel.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>