qcacmn: Add version to regulatory database

Regdb SW needs to be versioned so that implementation
can be mapped to published QCA regulatory database.

Change-Id: I925f9953f410507417747793381fd2f4b196f759
CRs-Fixed: 2354364

umac/regulatory/core/src/reg_db.c

@@ -19,7 +19,8 @@
 
 /**
  * DOC: reg_db.c
- * This file provides regulatory data base
+ * This file implements QCA regulatory database.
+ * Current implementation conforms to database version 26
  */
 
 #include <qdf_types.h>