dt-bindings: arm: sunxi: document MangoPi MQ-R board names

The MangoPi MQ-R board is a small development board, using Allwinner
SoCs with co-packaged DRAM. There are versions with a RISC-V core and
ones with two Arm Cortex-A7 cores.

Add the board/SoC compatible string pair to the list of known boards.

Signed-off-by: Andre Przywara <[e-mail]>
Acked-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jernej Skrabec <[e-mail]>

Documentation/devicetree/bindings/arm/sunxi.yaml

···
           - const: wexler,tab7200
           - const: allwinner,sun7i-a20
 
+      - description: MangoPi MQ-R board
+        items:
+          - const: widora,mangopi-mq-r-t113
+          - const: allwinner,sun8i-t113s
+
       - description: WITS A31 Colombus Evaluation Board
         items:
           - const: wits,colombus

Documentation/devicetree/bindings/riscv/sunxi.yaml

···
           - const: widora,mangopi-mq-pro
           - const: allwinner,sun20i-d1
 
+      - description: MangoPi MQ-R board
+        items:
+          - const: widora,mangopi-mq-r-f133
+          - const: allwinner,sun20i-d1s
+
 additionalProperties: true
 
 ...