[ARM] mmp: fix clock tick rate in mmp2

In MMP2, clock tick rate should be 6500000.
Signed-off-by: NMingliang Hu <mhu4@marvell.com>
Signed-off-by: NHaojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: NEric Miao <eric.y.miao@gmail.com>

arch/arm/mach-mmp/include/mach/timex.h

@@ -6,4 +6,8 @@
  * published by the Free Software Foundation.
  */
 
+#ifdef CONFIG_CPU_MMP2
+#define CLOCK_TICK_RATE		6500000
+#else
 #define CLOCK_TICK_RATE		3250000
+#endif