Add pwm nodes for RK3528. Most rk3528 boards use pwm-regulator to
supply to CPU, add node to enable them. The PWM core on RK3528 is
the same as RK3328, but the driver doesn't support interrupts yet.

Note that pwm regulator needs to be initialized in U-Boot:
```
&vdd_arm {
	regulator-init-microvolt = <953000>;
};

&vdd_logic {
	regulator-init-microvolt = <900000>;
};
```

Changes in v3:
  Adjust regulators order of E20C dts nodes
  Use PWM_POLARITY_INVERTED in pwm-regulator

Changes in v2:
  Remove merged bindings patch
  Remove pwm pinctrl in rk3528.dtsi
  Enable pwm regulator for Radxa E20C

Chukun Pan (2):
  arm64: dts: rockchip: Add pwm nodes for RK3528
  arm64: dts: rockchip: Enable regulators for Radxa E20C

 .../boot/dts/rockchip/rk3528-radxa-e20c.dts   | 73 +++++++++++++++++
 arch/arm64/boot/dts/rockchip/rk3528.dtsi      | 80 +++++++++++++++++++
 2 files changed, 153 insertions(+)

-- 
2.25.1