regulator: rk8xx: Fix buck get and set enabled state on RK806

Wrong POWER_EN reg is used to get and set enabled state for the RK806
buck 4 and 8 regulators, also wrong POWER_SLP_EN0 bit is used for
suspend state for the RK806 buck 1-8 regulators.

Fix this by not adding one to the zero based buck variable.

Fixes: f172575d92cd ("power: rk8xx: add support for RK806")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
diff --git a/drivers/power/regulator/rk8xx.c b/drivers/power/regulator/rk8xx.c
index 34e6151..b910943 100644
--- a/drivers/power/regulator/rk8xx.c
+++ b/drivers/power/regulator/rk8xx.c
@@ -415,7 +415,7 @@
 		break;
 	case RK806_ID:
 		value = RK806_POWER_EN_CLRSETBITS(buck % 4, enable);
-		en_reg = RK806_POWER_EN((buck + 1) / 4);
+		en_reg = RK806_POWER_EN(buck / 4);
 		ret = pmic_reg_write(pmic, en_reg, value);
 		break;
 	case RK808_ID:
@@ -494,7 +494,7 @@
 		break;
 	case RK806_ID:
 		mask = BIT(buck % 4);
-		ret = pmic_reg_read(pmic, RK806_POWER_EN((buck + 1) / 4));
+		ret = pmic_reg_read(pmic, RK806_POWER_EN(buck / 4));
 		break;
 	case RK808_ID:
 	case RK818_ID:
@@ -544,7 +544,7 @@
 				mask = BIT(buck + 1 - 3);
 			} else {
 				reg = RK806_POWER_SLP_EN0;
-				mask = BIT(buck + 1);
+				mask = BIT(buck);
 			}
 			ret = pmic_clrsetbits(pmic, reg, mask, enable ? mask : 0);
 		}
@@ -595,7 +595,7 @@
 				mask = BIT(buck + 1 - 3);
 			} else {
 				reg = RK806_POWER_SLP_EN0;
-				mask = BIT(buck + 1);
+				mask = BIT(buck);
 			}
 			val = pmic_reg_read(pmic, reg);
 		}