[LLVM] Update ARM maintainer

Author: nikic

llvm/Maintainers.md

@@ -180,8 +180,8 @@ [email protected] (email), [markschimmel](https://github.com/markschimmel) (Gi
 
 #### ARM backend
 
-Renato Golin \
-[email protected] (email), [rengolin](https://github.com/rengolin) (GitHub)
+David Green \
+[email protected] (email), [davemgreen](https://github.com/davemgreen) (GitHub)
 
 #### AVR backend
 
@@ -470,6 +470,7 @@ [email protected] (email), [lattner](https://github.com/lattner) (GitHub), clattn
 
 Justin Bogner ([email protected], [bogner](https://github.com/bogner)) -- SelectionDAG \
 Evan Cheng ([email protected]) -- Parts of code generator not covered by someone else \
+Renato Golin ([email protected]), [rengolin](https://github.com/rengolin)) -- ARM backend \
 Hans Wennborg ([email protected], [zmodem](https://github.com/zmodem)) -- Release management \
 
 ### Former maintainers of removed components