ARM: EXYNOS4: remove duplicated inclusion

Remove duplicated #include('s) in
  arch/arm/mach-exynos4/cpu.c
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos4/cpu.c

@@ -24,7 +24,6 @@
 #include <plat/exynos4.h>
 #include <plat/adc-core.h>
 #include <plat/sdhci.h>
-#include <plat/devs.h>
 #include <plat/fb-core.h>
 #include <plat/fimc-core.h>
 #include <plat/iic-core.h>