mbed-os5 only for TYBLE16

Dependents:   TYBLE16_simple_data_logger TYBLE16_MP3_Air

Revision:
0:5b88d5760320
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/device_key/mbed_lib.json	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,3 @@
+{
+    "name": "device_key"
+}