ARM: EXYNOS: convert cpuidle driver to be a platform driver

ARM EXYNOS cpuidle driver is currently not multiplatform support
ready (as it uses device_initcall() for initialization and doesn't
check on what platform it is running). Fix it by converting the
driver to be a platform driver and registering exynos_cpuidle
platform device from exynos[4,5]_dt_machine_init().

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c
index ac139226..1bde6ad 100644
--- a/arch/arm/mach-exynos/cpuidle.c
+++ b/arch/arm/mach-exynos/cpuidle.c
@@ -15,6 +15,7 @@
 #include <linux/io.h>
 #include <linux/export.h>
 #include <linux/time.h>
+#include <linux/platform_device.h>
 
 #include <asm/proc-fns.h>
 #include <asm/smp_scu.h>
@@ -192,7 +193,7 @@
 	__raw_writel(tmp, EXYNOS5_PWR_CTRL2);
 }
 
-static int __init exynos4_init_cpuidle(void)
+static int __init exynos_cpuidle_probe(struct platform_device *pdev)
 {
 	int cpu_id, ret;
 	struct cpuidle_device *device;
@@ -226,4 +227,13 @@
 
 	return 0;
 }
-device_initcall(exynos4_init_cpuidle);
+
+static struct platform_driver exynos_cpuidle_driver = {
+	.probe	= exynos_cpuidle_probe,
+	.driver = {
+		.name = "exynos_cpuidle",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(exynos_cpuidle_driver);