feat(rdfremont): fetch attestation key and token from RSE

Use the delegated attestation driver to fetch platform attestation token
and Realm attestation key from RSE over the AP-RSE comms interface.

Signed-off-by: Rohit Mathew <Rohit.Mathew@arm.com>
Signed-off-by: Vivek Gautam <vivek.gautam@arm.com>
Change-Id: Id0cfd82ef79598cd8368ba017c145bf34d502e65
3 files changed