regulator: Only update [LDOx|DCx]_HIB_MODE bits in wm8350_[ldo|dcdc]_set_suspend_disable

What we want is to disable output by setting [LDOx|DCx]_HIB_MODE bits.
Current code also clears other bits in LDOx/DCDCx Low Power register.

R202 (CAh) LDO1 Low Power
BIT[13:12] LDO1 Hibernate behaviour:
00 = Select voltage image settings
01 = disable output
10 = reserved
11 = reserved

R182 (B6h) DCDC1 Low Power
BIT[14:12] DC-DC1 Hibernate behaviour:
000 = Use current settings (no change)
001 = Select voltage image settings
010 = Force standby mode
011 = Force standby mode and voltage image settings.
100 = Force LDO mode
101 = Force LDO mode and voltage image settings.
110 = Reserved.
111 = Disable output

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/wm8350-regulator.c b/drivers/regulator/wm8350-regulator.c
index c5f3b40..05ecfb8 100644
--- a/drivers/regulator/wm8350-regulator.c
+++ b/drivers/regulator/wm8350-regulator.c
@@ -535,25 +535,25 @@
 		val = wm8350_reg_read(wm8350, WM8350_DCDC1_LOW_POWER);
 		wm8350->pmic.dcdc1_hib_mode = val & WM8350_DCDC_HIB_MODE_MASK;
 		wm8350_reg_write(wm8350, WM8350_DCDC1_LOW_POWER,
-			WM8350_DCDC_HIB_MODE_DIS);
+				 val | WM8350_DCDC_HIB_MODE_DIS);
 		break;
 	case WM8350_DCDC_3:
 		val = wm8350_reg_read(wm8350, WM8350_DCDC3_LOW_POWER);
 		wm8350->pmic.dcdc3_hib_mode = val & WM8350_DCDC_HIB_MODE_MASK;
 		wm8350_reg_write(wm8350, WM8350_DCDC3_LOW_POWER,
-			WM8350_DCDC_HIB_MODE_DIS);
+				 val | WM8350_DCDC_HIB_MODE_DIS);
 		break;
 	case WM8350_DCDC_4:
 		val = wm8350_reg_read(wm8350, WM8350_DCDC4_LOW_POWER);
 		wm8350->pmic.dcdc4_hib_mode = val & WM8350_DCDC_HIB_MODE_MASK;
 		wm8350_reg_write(wm8350, WM8350_DCDC4_LOW_POWER,
-			WM8350_DCDC_HIB_MODE_DIS);
+				 val | WM8350_DCDC_HIB_MODE_DIS);
 		break;
 	case WM8350_DCDC_6:
 		val = wm8350_reg_read(wm8350, WM8350_DCDC6_LOW_POWER);
 		wm8350->pmic.dcdc6_hib_mode = val & WM8350_DCDC_HIB_MODE_MASK;
 		wm8350_reg_write(wm8350, WM8350_DCDC6_LOW_POWER,
-			WM8350_DCDC_HIB_MODE_DIS);
+				 val | WM8350_DCDC_HIB_MODE_DIS);
 		break;
 	case WM8350_DCDC_2:
 	case WM8350_DCDC_5:
@@ -749,7 +749,7 @@
 
 	/* all LDOs have same mV bits */
 	val = wm8350_reg_read(wm8350, volt_reg) & ~WM8350_LDO1_HIB_MODE_MASK;
-	wm8350_reg_write(wm8350, volt_reg, WM8350_LDO1_HIB_MODE_DIS);
+	wm8350_reg_write(wm8350, volt_reg, val | WM8350_LDO1_HIB_MODE_DIS);
 	return 0;
 }