host/mesh: Allow to be NODE when PROVISIONER is enabled
host/mesh: Allow to be NODE when PROVISIONER is enabled

When PROVISIONER and CDB is enabled then IUT couldn't be a NODE.
This patch fixes this by not returning an error when CDB is not
configured. This is useful especially in testing environment, when all
the features are compiled in and we can choose role in runtime.

This is port of b9c8d270ab642ae18c83aad66ab5e1d962de74d3

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble