dt-bindings: arm: rockchip: Add Radxa Compute Module 3

dt-bindings: arm: rockchip: Add Radxa Compute Module 3

Radxa Compute Module 3(CM3) is one of the modules from a series
System On Module based on the Radxa ROCK 3 series and is compatible
with Raspberry Pi CM4 in pinout and form factor.

Specification:
- Rockchip RK3566
- up to 8GB LPDDR4
- up to 128GB high performance eMMC
- Optional wireless LAN, 2.4GHz and 5.0GHz IEEE 802.11b/g/n/ac wireless,
  BT 5.0, BLE with onboard and external antenna.
- Gigabit Ethernet PHY

Add dt-bindings for Radxa CM3.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230112105902.192852-1-jagan@amarulasolutions.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>