dt-bindings: arm: mstar: Add compatible for Miyoo Mini

The Miyoo Mini is a SigmaStar SSD202D based retro emulation
device.

Add a compatible for it to the list of infinity2m devices.

Link: http://linux-chenxing.org/infinity2/miyoomini/
Signed-off-by: Daniel Palmer <[e-mail]>
Acked-by: Rob Herring <[e-mail]>

Documentation/devicetree/bindings/arm/mstar/mstar.yaml

···
           - enum:
               - honestar,ssd201htv2 # Honestar SSD201_HT_V2 devkit
               - m5stack,unitv2 # M5Stack UnitV2
+              - miyoo,miyoo-mini # Miyoo Mini
               - wirelesstag,ido-som2d01 # Wireless Tag IDO-SOM2D01
               - wirelesstag,ido-sbc2d06-v1b-22w # Wireless Tag IDO-SBC2D06-1VB-22W
           - const: mstar,infinity2m