Update CODEOWNERS (#10583)

* Update CODEOWNERS

Scope to storage data-plane only

* Update CODEOWNERS

Author: kasobol-msft

CODEOWNERS

@@ -66,7 +66,8 @@
 /specification/servicebus/ @sazeesha @v-ajnava
 /specification/servicefabric/ @juhacket @samedder
 /specification/sql/ @jaredmoo @jamestao
-/specification/storage/ @blueww @jasonyang-msft @xiaonlimsft @kasobol-msft
+/specification/storage/ @blueww @jasonyang-msft @xiaonlimsft
+/specification/storage/data-plane/ @kasobol-msft @seanmcc-msft
 /specification/storageimportexport/ @leoz-ms
 /specification/storagesync/ @ankushbindlish2
 /specification/storsimple8000series/ @manaas-microsoft