ARM: exynos: Fix warning due to missing 'inline' in stub

In file included from arch/arm/mach-exynos/clock-exynos5.c:29:0:
arch/arm/mach-exynos/common.h:28:12: warning: 'exynos_pm_late_initcall' defined but not used [-Wunused-function]
Signed-off-by: NOlof Johansson <olof@lixom.net>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Shawn Guo <shawn.guo@linaro.org>

arch/arm/mach-exynos/common.h

@@ -25,7 +25,7 @@ void exynos_init_late(void);
 #ifdef CONFIG_PM_GENERIC_DOMAINS
 int exynos_pm_late_initcall(void);
 #else
-static int exynos_pm_late_initcall(void) { return 0; }
+static inline int exynos_pm_late_initcall(void) { return 0; }
 #endif
 
 #ifdef CONFIG_ARCH_EXYNOS4