Add 600Mhz freq defines for MX51

[Alexander Shiyan]

--- barebox-v2011.09.0.orig/arch/arm/mach-imx/include/mach/clock-imx51_53.h	2011-08-26 18:23:46.000000000 +0400
+++ barebox-v2011.09.0/arch/arm/mach-imx/include/mach/clock-imx51_53.h	2011-09-06 14:54:28.000000000 +0400
@@ -606,6 +606,10 @@
 #define MX5_PLL_DP_MFD_665	(96 - 1)
 #define MX5_PLL_DP_MFN_665	89

+#define MX5_PLL_DP_OP_600	((6 << 4) + ((1 - 1)  << 0))
+#define MX5_PLL_DP_MFD_600	(4 - 1)
+#define MX5_PLL_DP_MFN_600	1
+
 #define MX5_PLL_DP_OP_532	((5 << 4) + ((1 - 1)  << 0))
 #define MX5_PLL_DP_MFD_532	(24 - 1)
 #define MX5_PLL_DP_MFN_532	13