Fix incorrect CPU micro-architecture metadata [#1]

This PR contains two set of changes.

The first commit rectifies incorrect data relative to Xeon Ex-... v4 and Xeon Ex-... v2 CPUs whose micro-architectures are incorrect. (v4 is Broadwell, but some v4 CPUs were classified as Sandy Bridge or Haswell incorrectly, v2 is Ivy Bridge, but a cluster was marked as Sandy Bridge instead).

The second commit tweaks the Ice Lake and Skylake metadata. Grid5k only uses the Scalable Processor (aka server) derivative of the micro-architecture. There was a mix of Ice Lake and Ice Lake-SP in the data, which is made coherent as Ice Lake-SP, and all Skylake are turned into Skylake-SP for consistency.

The hardware.rb file is updated with the correct release date for those two micro-architecture, and the client ones are commented out.

It resolves the issue #1 I opened when I first noticed the issues.