Make sleep work again when BLE is disabled

In commit 4944aa48 ("fix(ble): Update to changes from new SDK") a call to BbDrvDisable() was added to sleep_deepsleep(). This function must, however, only be called when BLE was previously initialized, otherwise a wakeup from deepsleep will not be possible (if it ever reaches it?).

Fix this by reworking the BLE enabled check to also be usable here, to only call BbDrvDisable() when BLE is active.

Fixes: 4944aa48 ("fix(ble): Update to changes from new SDK")
Fixes: #231 (closed)

epicardium/ble/ble.c

@@ -269,17 +269,26 @@ void RSV11_IRQHandler(void)
 	notify();
 }
 /*************************************************************************************************/
-bool ble_shall_start(void)
+bool ble_is_enabled(void)
 {
-	bool ble_enabled = config_get_boolean_with_default("ble_enable", false);
+	/*
+	 * 0 = unknown, check config
+	 * 1 = disabled
+	 * 2 = enabled
+	 */
+	static int ble_state = 0;
 
-	if (ble_enabled) {
-		LOG_INFO("ble", "BLE is enabled.");
-	} else {
-		LOG_INFO("ble", "BLE is disabled.");
+	if (ble_state == 0) {
+		if (config_get_boolean_with_default("ble_enable", false)) {
+			ble_state = 2;
+			LOG_INFO("ble", "BLE is enabled.");
+		} else {
+			ble_state = 1;
+			LOG_INFO("ble", "BLE is disabled.");
+		}
 	}
 
-	return ble_enabled;
+	return ble_state == 2;
 }
 /*************************************************************************************************/
 static void scheduleTimer(void)