ARM: dts: aspeed: Add YADRO VESNIN BMC

VESNIN is an OpenPower machine with an Aspeed 2400 BMC SoC manufactured
by YADRO.

Signed-off-by: Alexander Filippov <a.filippov@yadro.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>