Fix compiling errors on nRF devices (#801)

* Fix undeclared 'nimble_port_stop()' on nRF51

* Fix missing member 'm_pClient' in NimBLEServer

src/NimBLEServer.cpp

@@ -70,9 +70,11 @@ NimBLEServer::~NimBLEServer() {
         delete m_pServerCallbacks;
     }
 
+# if defined(CONFIG_BT_NIMBLE_ROLE_CENTRAL)
     if (m_pClient != nullptr) {
         delete m_pClient;
     }
+# endif
 }
 
 /**
@@ -399,10 +401,12 @@ int NimBLEServer::handleGapEvent(ble_gap_event* event, void* arg) {
                 }
             }
 
+# if defined(CONFIG_BT_NIMBLE_ROLE_CENTRAL)
             if (pServer->m_pClient && pServer->m_pClient->m_connHandle == event->disconnect.conn.conn_handle) {
                 // If this was also the client make sure it's flagged as disconnected.
                 pServer->m_pClient->m_connHandle = BLE_HS_CONN_HANDLE_NONE;
             }
+# endif
 
             if (pServer->m_svcChanged) {
                 pServer->resetGATT();

src/nimble/porting/nimble/src/nimble_port.c

@@ -47,6 +47,7 @@
 #if !CONFIG_BT_CONTROLLER_ENABLED
 #include "nimble/nimble/transport/include/nimble/transport.h"
 #endif
+#endif
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
@@ -84,6 +85,7 @@ nimble_port_stop_cb(struct ble_npl_event *ev)
     ble_npl_sem_release(&ble_hs_stop_sem);
 }
 
+#ifdef ESP_PLATFORM
 /**
  * @brief esp_nimble_init - Initialize the NimBLE host stack
  *
@@ -324,11 +326,6 @@ IRAM_ATTR nimble_port_get_dflt_eventq(void)
 
 #else // ESP_PLATFORM
 
-static struct ble_npl_eventq g_eventq_dflt;
-
-extern void os_msys_init(void);
-extern void os_mempool_module_init(void);
-
 void
 nimble_port_init(void)
 {
@@ -360,6 +357,39 @@ nimble_port_init(void)
 #endif
 }
 
+int
+nimble_port_stop(void)
+{
+    int rc = 0;
+
+    rc = ble_npl_sem_init(&ble_hs_stop_sem, 0);
+    if (rc != 0) {
+        return rc;
+    }
+
+    /* Initiate a host stop procedure. */
+    rc = ble_hs_stop(&stop_listener, ble_hs_stop_cb,
+            NULL);
+    if (rc != 0) {
+        ble_npl_sem_deinit(&ble_hs_stop_sem);
+        return rc;
+    }
+
+    /* Wait till the host stop procedure is complete */
+    ble_npl_sem_pend(&ble_hs_stop_sem, BLE_NPL_TIME_FOREVER);
+
+    ble_npl_event_init(&ble_hs_ev_stop, nimble_port_stop_cb,
+                       NULL);
+    ble_npl_eventq_put(&g_eventq_dflt, &ble_hs_ev_stop);
+
+    /* Wait till the event is serviced */
+    ble_npl_sem_pend(&ble_hs_stop_sem, BLE_NPL_TIME_FOREVER);
+
+    ble_npl_sem_deinit(&ble_hs_stop_sem);
+
+    return rc;
+}
+
 void
 nimble_port_deinit(void)
 {