ARM: dts: aspeed: Add device tree for Nvidia's GB200NVL BMC

ARM: dts: aspeed: Add device tree for Nvidia's GB200NVL BMC

The GB200NVL BMC is an Aspeed Ast2600 based BMC [1] for Nvidia Blackwell
GB200NVL platform [2].

Co-developed-by: Mars Yang <maryang@nvidia.com>
Signed-off-by: Mars Yang <maryang@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Andrew Jeffery <andrew@codeconstruct.com.au>
Link: https://www.aspeedtech.com/server_ast2600/
Link: https://nvdam.widen.net/s/wwnsxrhm2w/blackwell-datasheet-3384703
Signed-off-by: Willie Thai <wthai@nvidia.com>
Link: https://patch.msgid.link/20250401153955.314860-3-wthai@nvidia.com
[arj: tidy commit message]
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>