MIPS: ralink: add uart mask to struct ralink_pinmux

Add a field for the uart muxing mask and set it inside the rt305x setup code.

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/5744/

arch/mips/ralink/common.h

@@ -22,6 +22,7 @@ struct ralink_pinmux {
 	struct ralink_pinmux_grp *mode;
 	struct ralink_pinmux_grp *uart;
 	int uart_shift;
+	u32 uart_mask;
 	void (*wdt_reset)(void);
 	struct ralink_pinmux_grp *pci;
 	int pci_shift;