ARM: dts: aspeed: Adding Facebook Yosemite V2 BMC

The Yosemite V2 is a facebook multi-node server
platform that host four OCP server. The BMC
in the Yosemite V2 platform based on AST2500 SoC.

This patch adds linux device tree entry related to
Yosemite V2 specific devices connected to BMC SoC.

Signed-off-by: Manikandan Elumalai <manikandan.hcl.ers.epl@gmail.com>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Vijay Khemka <vkhemka@fb.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>