ARM: SAMSUNG: Fix UART number for S5P6442

The recent changes in the UART code mean that we need to ensure that
the 4 UART case is only selected if S5PV210 is being compiled.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 86590e9..c53e13a 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -552,7 +552,7 @@
 config SERIAL_S5PV210
 	tristate "Samsung S5PV210 Serial port support"
 	depends on SERIAL_SAMSUNG && (CPU_S5PV210 || CPU_S5P6442)
-	select SERIAL_SAMSUNG_UARTS_4
+	select SERIAL_SAMSUNG_UARTS_4 if CPU_S5PV210
 	default y
 	help
 	  Serial port support for Samsung's S5P Family of SoC's