ARM: dts: aspeed: asrock: Add ASRock X570D4U BMC

ARM: dts: aspeed: asrock: Add ASRock X570D4U BMC

This is a relatively low-cost AST2500-based Amd Ryzen 5000 Series
micro-ATX board that we hope can provide a decent platform for OpenBMC
development.

This initial device-tree provides the necessary configuration for
basic BMC functionality such as serial console, KVM support
and POST code snooping.

Signed-off-by: Renze Nicolai <renze@rnplus.nl>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20231202003908.3635695-3-renze@rnplus.nl
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>