board: rockchip: Add vdd_cpu reg fixup for RGXX3 Series

board: rockchip: Add vdd_cpu reg fixup for RGXX3 Series

Some of the Powkiddy devices switched to using a different vendor for
the vdd_cpu regulator. Unfortunately the device does not have a new
revision to denote this, so users have no way of knowing in advance.

Add code to detect if a device is present at addresses 0x1c or 0x40 on
the i2c0 bus and update the devicetree if needed.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>