meta-ampere: Add Thu Nguyen as an OWNER

Remove Tung Nguyen and add Thu Nguyen

Signed-off-by: Thang Q. Nguyen <thang@os.amperecomputing.com>
Change-Id: I7821acbf89e5b43608c87bea302daca5958df0ae
diff --git a/meta-ampere/OWNERS b/meta-ampere/OWNERS
index d759f31..7df1f1d 100644
--- a/meta-ampere/OWNERS
+++ b/meta-ampere/OWNERS
@@ -1,3 +1,3 @@
 owners:
 - thang@os.amperecomputing.com
-- tungnguyen@os.amperecomputing.com
+- thu@os.amperecomputing.com