mfd: Staticise non-exported tps65217_update_bits()

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/tps65217.c b/drivers/mfd/tps65217.c
index c064c0a..db194e4 100644
--- a/drivers/mfd/tps65217.c
+++ b/drivers/mfd/tps65217.c
@@ -96,7 +96,7 @@
  * @val: Value to write.
  * @level: Password protected level
  */
-int tps65217_update_bits(struct tps65217 *tps, unsigned int reg,
+static int tps65217_update_bits(struct tps65217 *tps, unsigned int reg,
 		unsigned int mask, unsigned int val, unsigned int level)
 {
 	int ret;