drivers/lwl: Fix lwl_console.c to support is own up_putc()

After removing stm32_serial.c compilation we need to create a new
up_putc() to be used by syslog.

Signed-off-by: Alan C. Assis <acassis@gmail.com>

drivers/misc/lwl_console.c

@@ -294,6 +294,22 @@ static ssize_t lwlconsole_write(FAR struct file *filep,
  * Public Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: up_putc
+ ****************************************************************************/
+
+void up_putc(int ch)
+{
+  /* If link not initialize just return */
+
+  if (!linkactive())
+    {
+      return;
+    }
+
+  write8bits(LWL_PORT_CONSOLE, (uint8_t)ch);
+}
+
 /****************************************************************************
  * Name: lwlconsole_init
  ****************************************************************************/