ARM: highbank: fix us_to_tick calculation

udelay calls were off due to failing to convert us to ns. Fix this and drop
the unnecessary shifts since NS_PER_TICK is only 7ns.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/arch/arm/cpu/armv7/highbank/timer.c b/arch/arm/cpu/armv7/highbank/timer.c
index d92503f..0f985e2 100644
--- a/arch/arm/cpu/armv7/highbank/timer.c
+++ b/arch/arm/cpu/armv7/highbank/timer.c
@@ -66,10 +66,10 @@
 
 static inline unsigned long long us_to_tick(unsigned long long us)
 {
-	unsigned long long tick = us << 16;
+	unsigned long long tick = us * 1000;
 	tick += NS_PER_TICK - 1;
 	do_div(tick, NS_PER_TICK);
-	return tick >> 16;
+	return tick;
 }
 
 unsigned long long get_ticks(void)