arm64: dts: allwinner: a523: add X96Q-Pro+ support

arm64: dts: allwinner: a523: add X96Q-Pro+ support

The X96QPro+ is a TV box using the Allwinner H728 SoC. That SoC seems to
be a package variant of the A523 family, at least it uses the same SoC
ID and is compatible as far as we can assess.

It comes with the following specs:
  - Allwinner H728 SoC: 8 Arm Cortex-A55 cores, Mali-G57 MC1 GPU
  - 2 or 4GiB DDR3L DRAM
  - 32, 64, or 128 GiB eMMC flash
  - AXP717 + AXP323 PMICs
  - Gigabit Ethernet (using MAXIO PHY)
  - HDMI port
  - 2 * USB 2.0 ports
  - 1 * USB 3.0 port
  - microSD card slot
  - TOSLINK digital audio output
  - 3.5mm A/V port
  - infrared sensor
  - 7-segment display
  - 5V barrel plug power supply
  - power button

The PCB provides holes for soldering a UART header or cable, this is
connected to the debug UART0. There is another set of UART pins
available. The board also features a FEL button (accessible through the
3.5mm socket) and a reset button (only accessible when case is open).

This .dts just describes the basic peripherals as far as we support them
at the moment. The PMIC rail assignments are reverse engineered as far
as possible, by dumping them from a running Android system, and correlating
them to other boards using the same SoC.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20250307005712.16828-13-andre.przywara@arm.com
[wens@csie.org: Squash in SD card detect pull resistor fix]
Link: https://patch.msgid.link/20250425003422.3465-1-andre.przywara@arm.com
Signed-off-by: Chen-Yu Tsai <wens@csie.org>