docs/interop/firmware.json: Add SEV-ES support

docs/interop/firmware.json: Add SEV-ES support

Create an enum definition, '@amd-sev-es', for SEV-ES and add documention
for the new enum. Add an example that shows some of the requirements for
SEV-ES, including not having SMM support and the requirement for an
X64-only build.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <b941a7ee105dfeb67607cf2d24dafcb82658b212.1619208498.git.thomas.lendacky@amd.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>