feat(plat/arm/fvp): enable RSS backend based measured boot

Enable the RSS backend based measured boot feature.
In the absence of RSS the mocked version of PSA APIs
are used. They always return with success and hard-code data.

Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: I7543e9033a7a21f1b836d911d8d9498c6e09b956
5 files changed