mfd: Staticise max77693 pm_ops

They're not referenced outside this file.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/max77693.c b/drivers/mfd/max77693.c
index 4055bc2..8eed0c4 100644
--- a/drivers/mfd/max77693.c
+++ b/drivers/mfd/max77693.c
@@ -213,7 +213,7 @@
 	return max77693_irq_resume(max77693);
 }
 
-const struct dev_pm_ops max77693_pm = {
+static const struct dev_pm_ops max77693_pm = {
 	.suspend = max77693_suspend,
 	.resume = max77693_resume,
 };