regulator: ad5398: Fix min/max current limit boundary checking

It is ok to request current limit with min_uA < chip->min_uA and
max_uA > chip->max_uA.

We need to set min_uA = chip->min_uA if (min_uA < chip->min_uA),
this ensures the equation to calcuate selator does not return negative number.

Also set max_uA = chip->max_uA if (max_uA > chip->max_uA), as suggested by
Sonic.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/ad5398.c

@@ -89,9 +89,12 @@ static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int
 	unsigned short data;
 	int ret;
 
-	if (min_uA > chip->max_uA || min_uA < chip->min_uA)
-		return -EINVAL;
-	if (max_uA > chip->max_uA || max_uA < chip->min_uA)
+	if (min_uA < chip->min_uA)
+		min_uA = chip->min_uA;
+	if (max_uA > chip->max_uA)
+		max_uA = chip->max_uA;
+
+	if (min_uA > chip->max_uA || max_uA < chip->min_uA)
 		return -EINVAL;
 
 	selector = DIV_ROUND_UP((min_uA - chip->min_uA) * chip->current_level,