ARM: EXYNOS: Fix build breakage cpuidle on !SMP

The Exynos cpuidle driver has coupled cpuidle built-in so it cannot be
built without SMP:

arch/arm/mach-exynos/pm.c: In function 'exynos_cpu0_enter_aftr':
arch/arm/mach-exynos/pm.c:246:4: error: implicit declaration of function 'arch_send_wakeup_ipi_mask' [-Werror=implicit-function-declaration]
arch/arm/mach-exynos/built-in.o: In function 'exynos_pre_enter_aftr':
../arch/arm/mach-exynos/pm.c:300: undefined reference to 'cpu_boot_reg_base'
arch/arm/mach-exynos/built-in.o: In function 'exynos_cpu1_powerdown':
../arch/arm/mach-exynos/pm.c:282: undefined reference to 'exynos_cpu_power_down'

Fix it by adding missing checks for SMP.
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>

arch/arm/mach-exynos/exynos.c

@@ -211,7 +211,7 @@ static void __init exynos_dt_machine_init(void)
 	if (!IS_ENABLED(CONFIG_SMP))
 		exynos_sysram_init();
 
-#ifdef CONFIG_ARM_EXYNOS_CPUIDLE
+#if defined(CONFIG_SMP) && defined(CONFIG_ARM_EXYNOS_CPUIDLE)
 	if (of_machine_is_compatible("samsung,exynos4210"))
 		exynos_cpuidle.dev.platform_data = &cpuidle_coupled_exynos_data;
 #endif

arch/arm/mach-exynos/pm.c

@@ -181,6 +181,7 @@ void exynos_enter_aftr(void)
 	cpu_pm_exit();
 }
 
+#if defined(CONFIG_SMP) && defined(CONFIG_ARM_EXYNOS_CPUIDLE)
 static atomic_t cpu1_wakeup = ATOMIC_INIT(0);
 
 static int exynos_cpu0_enter_aftr(void)
@@ -302,3 +303,4 @@ struct cpuidle_exynos_data cpuidle_coupled_exynos_data = {
 	.pre_enter_aftr		= exynos_pre_enter_aftr,
 	.post_enter_aftr		= exynos_post_enter_aftr,
 };
+#endif /* CONFIG_SMP && CONFIG_ARM_EXYNOS_CPUIDLE */

drivers/cpuidle/cpuidle-exynos.c

@@ -117,7 +117,8 @@ static int exynos_cpuidle_probe(struct platform_device *pdev)
 {
 	int ret;
 
-	if (of_machine_is_compatible("samsung,exynos4210")) {
+	if (IS_ENABLED(CONFIG_SMP) &&
+	    of_machine_is_compatible("samsung,exynos4210")) {
 		exynos_cpuidle_pdata = pdev->dev.platform_data;
 
 		ret = cpuidle_register(&exynos_coupled_idle_driver,