Return correct value for fpi clock on ar9.

Signed-off-by: Ben Mulvihill <ben.mulvihill@gmail.com>
---
 arch/mips/lantiq/xway/clk.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/arch/mips/lantiq/xway/clk.c	2015-01-21 10:15:44.000000000 +0100
+++ b/arch/mips/lantiq/xway/clk.c	2015-01-21 10:17:29.000000000 +0100
@@ -104,8 +104,9 @@ unsigned long ltq_ar9_fpi_hz(void)
 	unsigned long sys = ltq_ar9_sys_hz();
 
 	if (ltq_cgu_r32(CGU_SYS) & BIT(0))
-		return sys;
-	return sys >> 1;
+		return sys / 3;
+	else
+		return sys / 2;
 }
 
 unsigned long ltq_ar9_cpu_hz(void)
