regulator: Fix WM831x regulator ID lookups for multiple WM831xs

With multiple wm831x devices the device IDs used for the regulators will
not always be contiguous so simply taking the modulus is not sufficient
to look up the ID, we need to reverse the way the ID is generated.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/wm831x-dcdc.c b/drivers/regulator/wm831x-dcdc.c
index a0982e8..0c7a9d5 100644
--- a/drivers/regulator/wm831x-dcdc.c
+++ b/drivers/regulator/wm831x-dcdc.c
@@ -504,11 +504,17 @@
 {
 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
-	int id = pdev->id % ARRAY_SIZE(pdata->dcdc);
+	int id;
 	struct wm831x_dcdc *dcdc;
 	struct resource *res;
 	int ret, irq;
 
+	if (pdata && pdata->wm831x_num)
+		id = (pdata->wm831x_num * 10) + 1;
+	else
+		id = 0;
+	id = pdev->id - id;
+
 	dev_dbg(&pdev->dev, "Probing DCDC%d\n", id + 1);
 
 	if (pdata == NULL || pdata->dcdc[id] == NULL)
@@ -709,11 +715,17 @@
 {
 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
-	int id = pdev->id % ARRAY_SIZE(pdata->dcdc);
+	int id;
 	struct wm831x_dcdc *dcdc;
 	struct resource *res;
 	int ret, irq;
 
+	if (pdata && pdata->wm831x_num)
+		id = (pdata->wm831x_num * 10) + 1;
+	else
+		id = 0;
+	id = pdev->id - id;
+
 	dev_dbg(&pdev->dev, "Probing DCDC%d\n", id + 1);
 
 	if (pdata == NULL || pdata->dcdc[id] == NULL)