regulator: tps6105x: add optional devicetree support

Tell the regulator framework to retrieve regulator init
data from the 'regulator' subnode, or from the parent mfd
device's platform data.

Example:

i2c0 {
	tps61052@33 {
		compatible = "ti,tps61052";
		reg = <0x33>;

		regulator {
			regulator-min-microvolt = <5000000>;
			regulator-max-microvolt = <5000000>;
			regulator-always-on;
		};
	};
};

Tree: next-20191118
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Link: https://lore.kernel.org/r/20191119154611.29625-3-TheSven73@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/tps6105x-regulator.c

@@ -37,6 +37,7 @@ static struct regulator_ops tps6105x_regulator_ops = {
 
 static const struct regulator_desc tps6105x_regulator_desc = {
 	.name		= "tps6105x-boost",
+	.of_match	= of_match_ptr("regulator"),
 	.ops		= &tps6105x_regulator_ops,
 	.type		= REGULATOR_VOLTAGE,
 	.id		= 0,
@@ -71,6 +72,7 @@ static int tps6105x_regulator_probe(struct platform_device *pdev)
 	config.dev = &tps6105x->client->dev;
 	config.init_data = pdata->regulator_data;
 	config.driver_data = tps6105x;
+	config.of_node = pdev->dev.parent->of_node;
 	config.regmap = tps6105x->regmap;
 
 	/* Register regulator with framework */