dt-bindings: arm: aspeed: add ASRock Rack ALTRAD8 board

Document ASRock Rack ALTRAD8 (ALTRAD8UD-1L2T and ALTRAD8UD2-1L2Q)
compatibles.

Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Tan Siewert <tan.siewert@hetzner.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20251218161816.38155-2-rebecca@bsdio.com
[arj: Drop erroneous Tested-by tag from Tan]
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

Author: bexcran

Documentation/devicetree/bindings/arm/aspeed/aspeed.yaml

@@ -34,6 +34,7 @@ properties:
               - amd,ethanolx-bmc
               - ampere,mtjade-bmc
               - aspeed,ast2500-evb
+              - asrock,altrad8-bmc
               - asrock,e3c246d4i-bmc
               - asrock,e3c256d4i-bmc
               - asrock,romed8hm3-bmc