ARM i.MX25: Add devicetree support

This adds a i.MX25 dt machine descriptor and changes the clock
support to optionally initialize from dt.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h
index ef8db6b..7191ab4 100644
--- a/arch/arm/mach-imx/common.h
+++ b/arch/arm/mach-imx/common.h
@@ -66,6 +66,7 @@
 			unsigned long ckih1, unsigned long ckih2);
 extern int mx53_clocks_init(unsigned long ckil, unsigned long osc,
 			unsigned long ckih1, unsigned long ckih2);
+extern int mx25_clocks_init_dt(void);
 extern int mx27_clocks_init_dt(void);
 extern int mx31_clocks_init_dt(void);
 extern int mx51_clocks_init_dt(void);