MAINTAINERS: Update collaborator for Renesas RA Platform

Add @thenguyenyf as collaborator for Renesas RA Platform

Signed-off-by: Thao Luong <thao.luong.uw@renesas.com>
diff --git a/MAINTAINERS.yml b/MAINTAINERS.yml
index 969e68f..0c9cfcc 100644
--- a/MAINTAINERS.yml
+++ b/MAINTAINERS.yml
@@ -4058,6 +4058,7 @@
   collaborators:
     - duynguyenxa
     - thaoluonguw
+    - thenguyenyf
   files:
     - boards/arduino/uno_r4/
     - boards/renesas/*ra*/