nimble/ll: Add option to initialize random device address by default

This adds an option to initialize random device address by default using
an address retrieved from an address provider.

Author: andrzej-kaczmarek

nimble/controller/src/ble_ll_addr.c

@@ -48,5 +48,12 @@ ble_ll_addr_init(void)
     ble_ll_addr_provide_public(g_dev_addr);
 #endif
 
+#if MYNEWT_VAL(BLE_LL_ADDR_INIT_RANDOM)
+    /* Set random address from provider API, if available */
+#if MYNEWT_API_ble_addr_provider_random
+    ble_ll_addr_provide_static(g_random_addr);
+#endif
+#endif
+
     return 0;
 }

nimble/controller/syscfg.yml

@@ -395,6 +395,12 @@ syscfg.defs:
                   not intended for production builds.
         value: 0x000000000000
 
+    BLE_LL_ADDR_INIT_RANDOM:
+        description: >
+            Initializes default random address with a static random address
+            retrieved from an address provider, if available.
+        value: 1
+
     BLE_LL_DTM:
         description: >
              Enables HCI Test commands needed for Bluetooth SIG certification