dt-bindings: arm: fsl: add TQMa8Mx boards

TQMa8Mx is a SOM family using NXP i.MX8M[Q,QL, D] CPU
MBa8Mx is a evaluation mainbord for this SOM

The SOM needs a mainboard, therefore we provide two compatibles here:

"tq,imx8mq-<SOM>" for the module and
"tq,imx8mq-<SOM>-<SBC>" for the module on that mainboard

Signed-off-by: Alexander Stein <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

Documentation/devicetree/bindings/arm/fsl.yaml

···
           - const: purism,librem5
           - const: fsl,imx8mq
 
+      - description:
+          TQMa8Mx is a series of SOM featuring NXP i.MX8MQ system-on-chip
+          variants. It is designed to be clicked on different carrier boards.
+        items:
+          - enum:
+              - tq,imx8mq-tqma8mq-mba8mx # TQ-Systems GmbH i.MX8MQ TQMa8Mx SOM on MBa8Mx
+          - const: tq,imx8mq-tqma8mq     # TQ-Systems GmbH i.MX8MQ TQMa8Mx SOM
+          - const: fsl,imx8mq
+
       - description: Zodiac Inflight Innovations Ultra Boards
         items:
           - enum: