Merge changes from topic "mb/mb-signer-id" into integration
* changes:
feat(qemu): add dummy plat_mboot_measure_key() function
docs(rss): update RSS doc for signer-ID
feat(imx): add dummy 'plat_mboot_measure_key' function
feat(tc): implement platform function to measure and publish Public Key
feat(auth): measure and publicise the Public Key
feat(fvp): implement platform function to measure and publish Public Key
feat(fvp): add public key-OID information in RSS metadata structure
feat(auth): add explicit entries for key OIDs
feat(rss): set the signer-ID in the RSS metadata
feat(auth): create a zero-OID for Subject Public Key
docs: add details about plat_mboot_measure_key function
feat(measured-boot): introduce platform function to measure and publish Public Key