ARM: EXYNOS: Fix "warning: initialization from incompatible pointer type"

Fix the wrong function prototype.
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/pm.c

@@ -206,7 +206,7 @@ static void exynos4_pm_prepare(void)
 
 }
 
-static int exynos4_pm_add(struct device *dev)
+static int exynos4_pm_add(struct device *dev, struct subsys_interface *sif)
 {
 	pm_cpu_prep = exynos4_pm_prepare;
 	pm_cpu_sleep = exynos4_cpu_suspend;