* the suspend mode config

- compatible: "rockchip,pm-config"
  Compatibility with rk3399

- rockchip,sleep-mode-config : the sleep mode config,
  ARMOFF, OSC disabled ...

- rockchip,wakeup-config: the wake up sourece enable.
  GPIO, USB, SD...

- rockchip,pwm-regulator-config: the pwm regulator name.

Example:
	rockchip_suspend: rockchip_suspend {
		compatible = "rockchip,pm-rk3399";
		status = "okay";
		rockchip,sleep-mode-config = <
			(0
			| RKPM_SLP_ARMPD
			| RKPM_SLP_PERILPPD
			| RKPM_SLP_DDR_RET
			| RKPM_SLP_PLLPD
			| RKPM_SLP_OSC_DIS
			| RKPM_SLP_CENTER_PD
			| RKPM_SLP_AP_PWROFF
			)
		>;
		rockchip,wakeup-config = <
			(0 |
			RKPM_GPIO_WKUP_EN |
			RKPM_PWM_WKUP_EN)
		>;
		rockchip,pwm-regulator-config = <
			(0 |
			PWM2_REGULATOR_EN
			)
		>;
	};