pmu-exynos522: export symbol exynos_pmu_wdt_control

Export symbol to avoid compilation error

Change-Id: Ia8062c713d847eb9a67ae9697bb9dcb42316ef1b

arch/arm/mach-exynos/pmu-exynos5422.c

@@ -557,6 +557,7 @@ void exynos_pmu_wdt_control(bool on, unsigned int pmu_wdt_reset_type)
 
 	return;
 }
+EXPORT_SYMBOL(exynos_pmu_wdt_control);
 
 void exynos_sys_powerdown_conf(enum sys_powerdown mode)
 {