serial: pch_uart: add terminate entry for dmi_system_id tables

Make sure dmi_system_id tables are NULL terminated.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/pch_uart.c

@@ -419,6 +419,7 @@ static struct dmi_system_id pch_uart_dmi_table[] = {
 		},
 		(void *)MINNOW_UARTCLK,
 	},
+	{ }
 };
 
 /* Return UART clock, checking for board specific clocks. */