dt-bindings: arm: rockchip: Add Pine64 SoQuartz SoM

The SoQuartz system on module is designed to be pin compatible with the
RPi CM4 SoM. It is based on the rk3566 SoC and outputs on uart2 for
debug and console. The first carrier board supported is the CM4IO board
from RPi.

Signed-off-by: Peter Geis <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Heiko Stuebner <[e-mail]>

Documentation/devicetree/bindings/arm/rockchip.yaml

···
               - pine64,quartz64-b
           - const: rockchip,rk3566
 
+      - description: Pine64 SoQuartz SoM
+        items:
+          - enum:
+              - pine64,soquartz-cm4io
+          - const: pine64,soquartz
+          - const: rockchip,rk3566
+
       - description: Radxa Rock
         items:
           - const: radxa,rock