mfd: rk8xx: Add support for RK806 power off

Use DEV_OFF bit to power off the RK806 PMIC, when system-power-controller
is used in DTS.

Signed-off-by: Ondrej Jirman <megi@xff.cz>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20231019165732.3818789-5-megi@xff.cz
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Ondrej Jirman

drivers/mfd/rk8xx-core.c

@@ -525,6 +525,10 @@ static int rk808_power_off(struct sys_off_data *data)
 		reg = RK805_DEV_CTRL_REG;
 		bit = DEV_OFF;
 		break;
+	case RK806_ID:
+		reg = RK806_SYS_CFG3;
+		bit = DEV_OFF;
+		break;
 	case RK808_ID:
 		reg = RK808_DEVCTRL_REG,
 		bit = DEV_OFF_RST;