ARM: EXYNOS: Use cpuidle_register

Use the cpuidle generic function 'cpuidle_register'. That saves us
from some extra lines of code and unneeded variables.

A side effect of this change is a bug fix where before the cpuidle
driver was registered for each_online_cpu and now it is for
each_possible_cpu.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/cpuidle.c

@@ -41,8 +41,6 @@
 
 #define S5P_CHECK_AFTR		0xFCBA0D10
 
-static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
-
 /* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */
 static void exynos4_set_wakeupmask(void)
 {
@@ -161,29 +159,17 @@ static struct cpuidle_driver exynos4_idle_driver = {
 
 static int exynos_cpuidle_probe(struct platform_device *pdev)
 {
-	int cpu_id, ret;
-	struct cpuidle_device *device;
+	int ret;
 
 	if (soc_is_exynos5440())
 		exynos4_idle_driver.state_count = 1;
 
-	ret = cpuidle_register_driver(&exynos4_idle_driver);
+	ret = cpuidle_register(&exynos4_idle_driver, NULL);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register cpuidle driver\n");
 		return ret;
 	}
 
-	for_each_online_cpu(cpu_id) {
-		device = &per_cpu(exynos4_cpuidle_device, cpu_id);
-		device->cpu = cpu_id;
-
-		ret = cpuidle_register_device(device);
-		if (ret) {
-			dev_err(&pdev->dev, "failed to register cpuidle device\n");
-			return ret;
-		}
-	}
-
 	return 0;
 }