nimble/controller: Use properties for storing advertising type
nimble/controller: Use properties for storing advertising type

This is in preparation for handling extended advertising PDUs. Legacy
advertising PDUs are mapped as describbed in Core Spec Vol. 2 Part E.
7.8.53 table 7.2.

X-Original-Commit: de29d08a03657887b3b24369f64a24e932588f5a

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