regulator: tps65217: Fix build warnings

rdev_get_id() returns an int. Convert rid to type int to avoid the
following warnings:

drivers/regulator/tps65217-regulator.c:73:10: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
drivers/regulator/tps65217-regulator.c:87:10: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]

Signed-off-by: Sachin Kamat <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/tps65217-regulator.c

···
 static int tps65217_pmic_enable(struct regulator_dev *dev)
 {
 	struct tps65217 *tps = rdev_get_drvdata(dev);
-	unsigned int rid = rdev_get_id(dev);
+	int rid = rdev_get_id(dev);
 
 	if (rid < TPS65217_DCDC_1 || rid > TPS65217_LDO_4)
 		return -EINVAL;
···
 static int tps65217_pmic_disable(struct regulator_dev *dev)
 {
 	struct tps65217 *tps = rdev_get_drvdata(dev);
-	unsigned int rid = rdev_get_id(dev);
+	int rid = rdev_get_id(dev);
 
 	if (rid < TPS65217_DCDC_1 || rid > TPS65217_LDO_4)
 		return -EINVAL;