Handle Asynchronous DDR clock on 85xx

The MPC8572 introduces the concept of an asynchronous DDR clock with
regards to the platform clock.

Introduce get_ddr_freq() to report the DDR freq regardless of sync/async
mode.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/cpu/mpc85xx/speed.c b/cpu/mpc85xx/speed.c
index 293269c..27de37a 100644
--- a/cpu/mpc85xx/speed.c
+++ b/cpu/mpc85xx/speed.c
@@ -48,6 +48,15 @@
 	 * overflow for processor speeds above 2GHz */
 	half_freqSystemBus = sysInfo->freqSystemBus/2;
 	sysInfo->freqProcessor = e500_ratio*half_freqSystemBus;
+	sysInfo->freqDDRBus = sysInfo->freqSystemBus;
+
+#ifdef CONFIG_DDR_CLK_FREQ
+	{
+		u32 ddr_ratio = ((gur->porpllsr) & 0x00003e00) >> 9;
+		if (ddr_ratio != 0x7)
+			sysInfo->freqDDRBus = ddr_ratio * CONFIG_DDR_CLK_FREQ;
+	}
+#endif
 }
 
 
@@ -93,3 +102,19 @@
 
 	return val;
 }
+
+/********************************************
+ * get_ddr_freq
+ * return ddr bus freq in Hz
+ *********************************************/
+ulong get_ddr_freq (ulong dummy)
+{
+	ulong val;
+
+	sys_info_t sys_info;
+
+	get_sys_info (&sys_info);
+	val = sys_info.freqDDRBus;
+
+	return val;
+}