SPINEL_PROP_MAC_SCAN_BEACON value

MAC Scan Beacon Format `Cct(ESSc)t(iCUdd)` - Asynchronous event only Scan beacons have two embedded structures which contain information about the MAC layer and the NET layer. Their format depends on the MAC and NET layer currently in use. The format below is for an 802.15.4 MAC with Thread: `C`: Channel `c`: RSSI of the beacon `t`: MAC layer properties (802.15.4 layer) `E`: Long address `S`: Short address `S`: PAN-ID `c`: LQI NET layer properties `i`: Protocol Number (SPINEL_PROTOCOL_TYPE_* values) `C`: Flags (SPINEL_BEACON_THREAD_FLAG_* values) `U`: Network Name `d`: XPANID `d`: Steering data Extra parameters may be added to each of the structures in the future, so care should be taken to read the length that prepends each structure.