ARM i.MX: Add common clock support for pllv1

The pllv1 is found on i.MX1, i.M25, i.MX27, i.MX31 and i.MX35.
Currently only reading the rate is supported.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h
index 00f2590..8a4aee6 100644
--- a/arch/arm/mach-imx/clk.h
+++ b/arch/arm/mach-imx/clk.h
@@ -5,7 +5,7 @@
 #include <linux/clk-provider.h>
 #include <mach/clock.h>
 
-struct clk *imx_clk_pllv1(const char *name, char *parent,
+struct clk *imx_clk_pllv1(const char *name, const char *parent,
 		void __iomem *base);
 
 static inline struct clk *imx_clk_fixed(const char *name, int rate)