regulator: Fix setting low power mode for wm831x aldo

Set BIT[8] of LDO7 ON Control mode for low power mode.

R16507 (407Bh)  LDO7 ON Control
BIT[8] LDO7_ON_MODE: LDO7 ON Operating Mode
        0 = Normal mode
        1 = Low Power mode
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/wm831x-ldo.c

@@ -506,22 +506,19 @@ static int wm831x_aldo_set_mode(struct regulator_dev *rdev,
 {
 	struct wm831x_ldo *ldo = rdev_get_drvdata(rdev);
 	struct wm831x *wm831x = ldo->wm831x;
-	int ctrl_reg = ldo->base + WM831X_LDO_CONTROL;
 	int on_reg = ldo->base + WM831X_LDO_ON_CONTROL;
 	int ret;
 
 
 	switch (mode) {
 	case REGULATOR_MODE_NORMAL:
-		ret = wm831x_set_bits(wm831x, on_reg,
-				      WM831X_LDO7_ON_MODE, 0);
+		ret = wm831x_set_bits(wm831x, on_reg, WM831X_LDO7_ON_MODE, 0);
 		if (ret < 0)
 			return ret;
 		break;
 
 	case REGULATOR_MODE_IDLE:
-		ret = wm831x_set_bits(wm831x, ctrl_reg,
-				      WM831X_LDO7_ON_MODE,
+		ret = wm831x_set_bits(wm831x, on_reg, WM831X_LDO7_ON_MODE,
 				      WM831X_LDO7_ON_MODE);
 		if (ret < 0)
 			return ret;