dtb: amd: Add support for new AMD Overdrive boards

Add device tree files for AMD Overdrive boards which comes with
AMD Seattle Revision B0 and B1 SOCs.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Olof Johansson <olof@lixom.net>