“Cat Stevens ... supported the fatwa against Salman Rushdie”
No. He was asked after a public lecture what the penalty for blasphemy was under Islamic law. He never claimed Rushdie had blasphemed Islam.
I take it that if a Christian or Jew were asked a similar question and they quoted Leviticus 24:16, you wouldn’t have your knickers in quite the same knot.
During that public lecture he (Stevens aka Islam) was asked, "You don't think man deserves to die?" and replied, "Who? Salmon Rushdie? Yes, yes..." (Yusuf Islam on UK TV 1989 Discussing Salmon Rusdie)