regulator: of: Add support for parsing microvolts for suspend state

Leverage all the work that was done in (40e20d68 regulator: of: Add
support for parsing regulator_state for suspend state) and throw in
the ability to set suspend microvolts from the device tree.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Chris Zhong <zyw@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/of_regulator.c

@@ -107,6 +107,10 @@ static void of_get_regulation_constraints(struct device_node *np,
 					"regulator-off-in-suspend"))
 			suspend_state->disabled = true;
 
+		if (!of_property_read_u32(suspend_np,
+					"regulator-suspend-microvolt", &pval))
+			suspend_state->uV = pval;
+
 		of_node_put(suspend_np);
 		suspend_state = NULL;
 		suspend_np = NULL;