Add myself as the the code owner for the AVR backend

Summary:
As I maintain the AVR backend and am currently in the process of migrating it in tree, it makes sense to add myself as the code owner.

Thoughts welcome!

Differential Revision: http://reviews.llvm.org/D14002

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251471 91177308-0d34-0410-b5e6-96231b3b80d8

CODE_OWNERS.TXT

@@ -118,6 +118,10 @@ N: David Majnemer
 E: david.majnemer@gmail.com
 D: IR Constant Folder, InstCombine
 
+N: Dylan McKay
+E: dylanmckay34@gmail.com
+D: AVR Backend
+
 N: Tim Northover
 E: t.p.northover@gmail.com
 D: AArch64 backend, misc ARM backend