[media] tua9001: use div_u64() for frequency calculation

Use div_u64() to simplify and remove home made divides.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
diff --git a/drivers/media/tuners/tua9001_priv.h b/drivers/media/tuners/tua9001_priv.h
index 327ead9..bc406c5 100644
--- a/drivers/media/tuners/tua9001_priv.h
+++ b/drivers/media/tuners/tua9001_priv.h
@@ -18,6 +18,7 @@
 #define TUA9001_PRIV_H
 
 #include "tua9001.h"
+#include <linux/math64.h>
 #include <linux/regmap.h>
 
 struct tua9001_reg_val {