ARM: dts: aspeed: Add Facebook Galaxy100 (AST2400) BMC

Add initial version of device tree for Facebook Galaxy100 (AST2400) BMC.

Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Reviewed-by: Patrick Williams <patrick@stwcx.xyz>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20201111232330.30843-5-rentao.bupt@gmail.com


Signed-off-by: Joel Stanley <joel@jms.id.au>