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/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index 24939ca..0efc815 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -317,9 +317,9 @@
 	serial_out(up, UART_DLM, value >> 8 & 0xff);
 }
 
-#ifdef CONFIG_MIPS_ALCHEMY
+#if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
 
-/* Au1x00 UART hardware has a weird register layout */
+/* Au1x00/RT288x UART hardware has a weird register layout */
 static const u8 au_io_in_map[] = {
 	[UART_RX]  = 0,
 	[UART_IER] = 2,
@@ -440,7 +440,7 @@
 		p->serial_out = mem32_serial_out;
 		break;
 
-#ifdef CONFIG_MIPS_ALCHEMY
+#if defined(CONFIG_MIPS_ALCHEMY) || defined(CONFIG_SERIAL_8250_RT288X)
 	case UPIO_AU:
 		p->serial_in = au_serial_in;
 		p->serial_out = au_serial_out;