[media] smiapp-pll: Constify limits argument to smiapp_pll_calculate()

The limits are input parameters and should not be modified by the
smiapp_pll_calculate() function. Make them const.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/i2c/smiapp-pll.h b/drivers/media/i2c/smiapp-pll.h
index 8500e6e..9491a41 100644
--- a/drivers/media/i2c/smiapp-pll.h
+++ b/drivers/media/i2c/smiapp-pll.h
@@ -107,7 +107,8 @@
 
 struct device;
 
-int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits,
+int smiapp_pll_calculate(struct device *dev,
+			 const struct smiapp_pll_limits *limits,
 			 struct smiapp_pll *pll);
 
 #endif /* SMIAPP_PLL_H */