[ARM] pxa: introduce sysdev for GPIO register saving/restoring

Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-pxa/generic.h b/arch/arm/mach-pxa/generic.h
index 367b679..1a16ad3 100644
--- a/arch/arm/mach-pxa/generic.h
+++ b/arch/arm/mach-pxa/generic.h
@@ -54,3 +54,4 @@
 #endif
 
 extern struct sysdev_class pxa_irq_sysclass;
+extern struct sysdev_class pxa_gpio_sysclass;