CODEOWNERS: add acrn-hypervisor Makefile owner
# Default/global reviewers (if not overridden later)
* @anthonyzxu @dongyaozu
+Makefile @binbinwu1
/hypervisor/ @anthonyzxu @dongyaozu
/devicemodel/ @anthonyzxu @ywan170
/doc/ @dbkinder @deb-intel @NanlinXie
