[llvm] [NFC][LLVM] Add RealtimeSanitizer LLVM code owners (PR #101231)

[Chris Apple via llvm-commits]

cjappl wrote:

CC Reviewers @vitalybuka @MaskRay @davidtrevelyan 

Because we don't have commiter access, not sure if this should just be closed! I defer to the reviewers if adding this in is appropriate or not.

Thanks as always.

https://github.com/llvm/llvm-project/pull/101231