ARM: dts: aspeed: Add device tree for Quanta S6Q BMC

The Quanta S6Q is a server platform with AST2600 BMC SoC

Signed-off-by: George Hung <george.hung@quantatw.com>
Reviewed-by: Alan Kuo <Alan_Kuo@quantatw.com>
Reviewed-by: P.K. Lee <p.k.lee@quantatw.com>
Link: https://lore.kernel.org/r/20220217031355.46102-1-george.hung@quantatw.com


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