Miscellaneous fixes targeting SCMI v3.2
Based on the latest master branch, the series includes:
- a bunch of general cleanup and fixes
- a bunch of fixes aimed at latest SCMIv3.2 testcases
- a few testcases-refactoring to simplify and unify some tests by providing the version to use as an input parameter (these tests were only slightly differing between SCMI versions depending on the version)
Tested on JUNO with SCP fw 2.15.0 and v6.13-rc1 Kernel.