[X86] SkylakeClientModel - conversion instructions don't use Port015

Fixes a lot of throughput mismatches - the more complicated conversion instructions use SKLPort5+SKLPort01, not SKLPort5+SKLPort015 (SKLPort015 is mainly used for basic Logic + blend ops)

Fixing this should allow us to remove a lot of unnecessary scheduler overrides from SkylakeClientModel

Confirmed by both Agner + uops.info