Update maintainer for lynxos178

Updates the listed maintainer for the lynxos178 platform in the platform support document.

No functional changes.

Author: rfatykhov-lynx

src/doc/rustc/src/platform-support/lynxos178.md

@@ -15,7 +15,7 @@ Target triples available:
 
 ## Target maintainers
 
-- Tim Newsome, https://github.com/tnewsome-lynx
+- Renat Fatykhov, https://github.com/rfatykhov-lynx
 
 ## Requirements