The value of tmnxMobPdnRfOcPrimaryCf specifies which compact flash
will be used as a primary storage for the Accounting Requests (ACR)
storage.
If the user tries to set the 'cf1' and if the 'cf1' is not available
then 'cf2' will be set as primary storage. If the user tries to set
the 'cf2' and if 'cf2' is not available then cf1 will be set as
primary storage. If both of the compact flash are not available then
value 'none' will be set.