add drv_ulog.h so that the project can built successfully

bsp/wch/risc-v/Libraries/ch32_drivers/drv_log.h

+/*
+ * Copyright (c) 2006-2022, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2018-11-15     SummerGift   first version
+ */
+
+/*
+ * NOTE: DO NOT include this file on the header file.
+ */
+
+#ifndef LOG_TAG
+#define DBG_TAG               "drv"
+#else
+#define DBG_TAG               LOG_TAG
+#endif /* LOG_TAG */
+
+#ifdef DRV_DEBUG
+#define DBG_LVL               DBG_LOG
+#else
+#define DBG_LVL               DBG_INFO
+#endif /* DRV_DEBUG */
+
+#include <rtdbg.h>