dt-bindings: arm: aspeed: Add compatible for Facebook Anacapa BMC

dt-bindings: arm: aspeed: Add compatible for Facebook Anacapa BMC

This patch adds the compatible string for the Facebook Anacapa BMC
which uses an Aspeed AST2600 SoC. This is required before adding
the board's device tree source file.

Signed-off-by: Peter Shen <sjg168@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
[arj: Insert provided Acked-by tag from Krzysztof, drop misspelled one]
Link: https://lore.kernel.org/linux-aspeed/259e917f-0570-40d6-983f-bfe9d77444a7@kernel.org/
Link: https://patch.msgid.link/20251219091632.1598603-2-sjg168@gmail.com
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>