[llvm] Add myself as the PS4/PS5 code owner (PR #108002)

[Paul T Robinson via llvm-commits]

https://github.com/pogo59 approved this pull request.

LGTM, although probably there should also be an entry in clang/CodeOwners.rst, as we--uh, Sony has a bunch of code sprinkled through Clang (driver target, lots of fiddly bits here and there, and a special case almost everywhere that there's an ABI difference to decide on).

https://github.com/llvm/llvm-project/pull/108002