serial: ralink: adds support for the serial core found on ralink wisoc

The MIPS based Ralink WiSoC platform has 1 or more 8250 compatible serial cores.
To make them work we require the same quirks that are used by AU1x00.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 82aebc8..d971421 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -134,7 +134,7 @@
 #define UPIO_HUB6		(1)
 #define UPIO_MEM		(2)
 #define UPIO_MEM32		(3)
-#define UPIO_AU			(4)			/* Au1x00 type IO */
+#define UPIO_AU			(4)			/* Au1x00 and RT288x type IO */
 #define UPIO_TSI		(5)			/* Tsi108/109 type IO */
 
 	unsigned int		read_status_mask;	/* driver specific */