serial: fix vr41xx_siu serial console support

The serial console can select only SERIAL_VR41XX=y.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/serial/vr41xx_siu.c b/drivers/serial/vr41xx_siu.c
index 0b35097..6fd51b0 100644
--- a/drivers/serial/vr41xx_siu.c
+++ b/drivers/serial/vr41xx_siu.c
@@ -65,7 +65,9 @@
 	},
 };
 
+#ifdef CONFIG_SERIAL_VR41XX_CONSOLE
 static uint8_t lsr_break_flag[SIU_PORTS_MAX];
+#endif
 
 #define siu_read(port, offset)		readb((port)->membase + (offset))
 #define siu_write(port, offset, value)	writeb((value), (port)->membase + (offset))