ARM: imx: add common clock support for pfd

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h
index 5f6e435..5297099 100644
--- a/arch/arm/mach-imx/clk.h
+++ b/arch/arm/mach-imx/clk.h
@@ -36,6 +36,9 @@
 			shift, 0, &imx_ccm_lock);
 }
 
+struct clk *imx_clk_pfd(const char *name, const char *parent_name,
+		void __iomem *reg, u8 idx);
+
 static inline struct clk *imx_clk_fixed(const char *name, int rate)
 {
 	return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);