regulator: core: Use a struct to pass in regulator runtime configuration

Rather than adding new arguments to regulator_register() every time we
want to add a new bit of dynamic information at runtime change the function
to take these via a struct. By doing this we avoid needing to do further
changes like the recent addition of device tree support which required each
regulator driver to be updated to take an additional parameter.

The regulator_desc which should (mostly) be static data is still passed
separately as most drivers are able to configure this statically at build
time.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/max8998.c b/drivers/regulator/max8998.c
index 5890265..74b0b0c 100644
--- a/drivers/regulator/max8998.c
+++ b/drivers/regulator/max8998.c
@@ -685,6 +685,7 @@
 {
 	struct max8998_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 	struct max8998_platform_data *pdata = dev_get_platdata(iodev->dev);
+	struct regulator_config config = { };
 	struct regulator_dev **rdev;
 	struct max8998_data *max8998;
 	struct i2c_client *i2c;
@@ -840,8 +841,12 @@
 			int count = (desc->max - desc->min) / desc->step + 1;
 			regulators[index].n_voltages = count;
 		}
-		rdev[i] = regulator_register(&regulators[index], max8998->dev,
-				pdata->regulators[i].initdata, max8998, NULL);
+
+		config.dev = max8998->dev;
+		config.init_data = pdata->regulators[i].initdata;
+		config.driver_data = max8998;
+
+		rdev[i] = regulator_register(&regulators[index], &config);
 		if (IS_ERR(rdev[i])) {
 			ret = PTR_ERR(rdev[i]);
 			dev_err(max8998->dev, "regulator init failed\n");