ARM: pxa: introduce pxa3xx_clock_sysclass for clock suspend/resume

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/arch/arm/mach-pxa/clock.h b/arch/arm/mach-pxa/clock.h
index 8ffc1d0..cf2cbd0 100644
--- a/arch/arm/mach-pxa/clock.h
+++ b/arch/arm/mach-pxa/clock.h
@@ -72,4 +72,6 @@
 
 extern void clk_pxa3xx_cken_enable(struct clk *);
 extern void clk_pxa3xx_cken_disable(struct clk *);
+
+extern struct sysdev_class pxa3xx_clock_sysclass;
 #endif