arm64: dts: allwinner: Add support for PinePhone revision 1.2

arm64: dts: allwinner: Add support for PinePhone revision 1.2

Revision 1.2 should be the final production version of the PinePhone.
It has most of the known HW quirks fixed.

Interrupt to the magnetometer is routed correctly, in this revision.

The bulk of the changes are in how modem and the USB-C HDMI bridge
chip is powered and where the signals from the modem are connected.

Also backlight intensity seemingly behaves differently, than on the
1.1 and 1.0 boards, and the PWM duty cycle where backlight starts
to work is 10% (as tested on 2 1.2 PinePhones I have access to).

Signed-off-by: Ondrej Jirman <megous@megous.com>
Link: https://lore.kernel.org/r/20200703194842.111845-3-megous@megous.com
Signed-off-by: Maxime Ripard <maxime@cerno.tech>