[X86] Cleanup WriteCvtSD2SS/WriteCvtPD2PS overrides

The WriteCvtSD2SS/WriteCvtPD2PS* classes were mostly unused as the models were needlessly overriding all instructions - in some cases the folded pattern overrides were entirely missing (but I've confirmed they just have an additional Port23 use)

There were a couple of typos (confirmed with Agner/uops.info) - Skylake/Icelake uses Port5+Port01 for XMM/YMM, Skylake uses Port5+Port05 for ZMM but Icelake uses Port5+Port0