doc: update CODEOWNERS for doc reviews
Deb (@deb-intel) added as a reviewer for ACRN documentation.
/hypervisor/ @anthonyzxu @dongyaozu
/devicemodel/ @anthonyzxu @dongyaozu
-/doc/ @dbkinder
+/doc/ @dbkinder @deb-intel
/tools/acrn-crashlog/ @dizhang417 @chengangc
-*.rst @dbkinder
+*.rst @dbkinder @deb-intel
