Add version numbers to titles of drivedb.h files on branches.

git-svn-id: https://svn.code.sf.net/p/smartmontools/code/branches/RELEASE_6_0_DRIVEDB@4164 4ea69e1a-61f1-4043-bf83-b5c94c648137

smartmontools/drivedb.h

 /*
- * drivedb.h - smartmontools drive database file
+ * drivedb.h - smartmontools 6.0 drive database file
  *
  * Home page of code is: http://www.smartmontools.org
  *