ARM: 6001/1: removing compilation warning comming from clkdev.h

clkdev.h is using struct device *. Due to this compilation
warning is comming. Removing this warning.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/clkdev.h

@@ -13,6 +13,7 @@
 #define __ASM_CLKDEV_H
 
 struct clk;
+struct device;
 
 struct clk_lookup {
 	struct list_head	node;