[ble] update BLE API docs to make platform's BLE advertising explicit (openthread#12913)

Also, changes term 'method' to correct term 'function'.

Author: EskoDijk

include/openthread/instance.h

@@ -52,7 +52,7 @@ extern "C" {
  *
  * @note This number versions both OpenThread platform and user APIs.
  */
-#define OPENTHREAD_API_VERSION (603)
+#define OPENTHREAD_API_VERSION (604)
 
 /**
  * @addtogroup api-instance

include/openthread/platform/ble.h

@@ -257,17 +257,18 @@ otError otPlatBleGapAdvStart(otInstance *aInstance, uint16_t aInterval);
 otError otPlatBleGapAdvStop(otInstance *aInstance);
 
 /**
- * The BLE driver calls this method to notify OpenThread that a BLE Central Device has
- * been connected.
+ * The BLE driver calls this function to notify OpenThread that a BLE Central Device has
+ * been connected. The BLE driver MUST stop advertising before calling this function.
  *
  * @param[in]  aInstance     The OpenThread instance structure.
  * @param[in]  aConnectionId The identifier of the open connection.
  */
 extern void otPlatBleGapOnConnected(otInstance *aInstance, uint16_t aConnectionId);
 
 /**
- * The BLE driver calls this method to notify OpenThread that the BLE Central Device
- * has been disconnected.
+ * The BLE driver calls this function to notify OpenThread that the BLE Central Device
+ * has been disconnected. The BLE driver MUST NOT start advertising before or after this
+ * call: this is controlled explicitly via otPlatBleGapAdvStart().
  *
  * @param[in]  aInstance     The OpenThread instance structure.
  * @param[in]  aConnectionId The identifier of the closed connection.
@@ -307,7 +308,7 @@ otError otPlatBleGapDisconnect(otInstance *aInstance);
 otError otPlatBleGattMtuGet(otInstance *aInstance, uint16_t *aMtu);
 
 /**
- * The BLE driver calls this method to notify OpenThread that ATT_MTU has been updated.
+ * The BLE driver calls this function to notify OpenThread that ATT_MTU has been updated.
  *
  * @param[in]  aInstance     The OpenThread instance structure.
  * @param[in]  aMtu          The updated ATT_MTU value. It MUST be >=OT_BLE_ATT_MTU_MIN.
@@ -335,7 +336,7 @@ extern void otPlatBleGattOnMtuUpdate(otInstance *aInstance, uint16_t aMtu);
 otError otPlatBleGattServerIndicate(otInstance *aInstance, uint16_t aHandle, const otBleRadioPacket *aPacket);
 
 /**
- * The BLE driver calls this method to notify OpenThread that an ATT Write Request
+ * The BLE driver calls this function to notify OpenThread that an ATT Write Request
  * packet has been received.
  *
  * @note This function shall be used only for GATT Server.