ARM: S3C24XX: use static declaration when it is not used in other files

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/plat-s3c24xx/s3c2443-clock.c b/arch/arm/plat-s3c24xx/s3c2443-clock.c
index 95e6819..037b448 100644
--- a/arch/arm/plat-s3c24xx/s3c2443-clock.c
+++ b/arch/arm/plat-s3c24xx/s3c2443-clock.c
@@ -53,7 +53,7 @@
  * elided as the EPLL can be either sourced by the XTAL or EXTCLK and as
  * such directly equating the two source clocks is impossible.
  */
-struct clk clk_mpllref = {
+static struct clk clk_mpllref = {
 	.name		= "mpllref",
 	.parent		= &clk_xtal,
 };