ARM: S3C24XX: Remove extern declaration of clk_msysclk

clk_msysclk is not needed outside of s3c2443-clock.c.

Removing the extern declaration will prevent conflicts with the
s3c2412 clk_msysclk in the following cleanups.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/plat-samsung/include/plat/s3c2443.h

@@ -51,4 +51,3 @@ extern int s3c2443_clkcon_enable_s(struct clk *clk, int enable);
 
 extern struct clksrc_clk clk_epllref;
 extern struct clksrc_clk clk_esysclk;
-extern struct clksrc_clk clk_msysclk;