ARM / PXA: Use struct syscore_ops for "core" power management

Replace sysdev classes and struct sys_device objects used for "core"
power management by the PXA platform code with struct syscore_ops
objects that are simpler.

This reduces the code size and the kernel memory footprint.  It also
is necessary for removing sysdevs entirely from the kernel in the
future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/arch/arm/mach-pxa/lubbock.c b/arch/arm/mach-pxa/lubbock.c
index 3ede978..e10ddb8 100644
--- a/arch/arm/mach-pxa/lubbock.c
+++ b/arch/arm/mach-pxa/lubbock.c
@@ -15,7 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
-#include <linux/sysdev.h>
+#include <linux/syscore_ops.h>
 #include <linux/major.h>
 #include <linux/fb.h>
 #include <linux/interrupt.h>
@@ -176,31 +176,22 @@
 
 #ifdef CONFIG_PM
 
-static int lubbock_irq_resume(struct sys_device *dev)
+static void lubbock_irq_resume(void)
 {
 	LUB_IRQ_MASK_EN = lubbock_irq_enabled;
-	return 0;
 }
 
-static struct sysdev_class lubbock_irq_sysclass = {
-	.name = "cpld_irq",
+static struct syscore_ops lubbock_irq_syscore_ops = {
 	.resume = lubbock_irq_resume,
 };
 
-static struct sys_device lubbock_irq_device = {
-	.cls = &lubbock_irq_sysclass,
-};
-
 static int __init lubbock_irq_device_init(void)
 {
-	int ret = -ENODEV;
-
 	if (machine_is_lubbock()) {
-		ret = sysdev_class_register(&lubbock_irq_sysclass);
-		if (ret == 0)
-			ret = sysdev_register(&lubbock_irq_device);
+		register_syscore_ops(&lubbock_irq_syscore_ops);
+		return 0;
 	}
-	return ret;
+	return -ENODEV;
 }
 
 device_initcall(lubbock_irq_device_init);