Add optional support for relaxed protocol versioning checks

Add an optional mechanism for relaxed protocol versioning checks in order
to let some testcases be run also against an SCMI server platform which
advertises a specific protocol version greater than the one currently
supported by the test suite.

Relaxed version checks support is currently optionally configurable only
for linux platform using a command option.
Note that, by default, strict version checking is instead carried on, as
it was before.

Optional relaxed protocol versioning checks support is then added to Base,
Performance, Power and Reset

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>