[RISCV] Remove some unnecessary UnsupportedSched* that are implied by others. NFC

Tablegen is missing a check that should have caught that these
were duplicated. I'm working to restore that check.

Author: topperc

llvm/lib/Target/RISCV/RISCVSchedMIPSP8700.td

@@ -277,5 +277,4 @@ defm : UnsupportedSchedSFB;
 defm : UnsupportedSchedZabha;
 defm : UnsupportedSchedXsfvcp;
 defm : UnsupportedSchedZvk;
-defm : UnsupportedSchedZvkned;
 }

llvm/lib/Target/RISCV/RISCVSchedSyntacoreSCR1.td

@@ -105,7 +105,6 @@ def : ReadAdvance<ReadIMul32, 0>;
 //===----------------------------------------------------------------------===//
 // Unsupported extensions
 defm : UnsupportedSchedA;
-defm : UnsupportedSchedD;
 defm : UnsupportedSchedF;
 defm : UnsupportedSchedSFB;
 defm : UnsupportedSchedV;
@@ -117,7 +116,6 @@ defm : UnsupportedSchedZbs;
 defm : UnsupportedSchedZbkb;
 defm : UnsupportedSchedZbkx;
 defm : UnsupportedSchedZfa;
-defm : UnsupportedSchedZfh;
 defm : UnsupportedSchedXsfvcp;
 defm : UnsupportedSchedZvk;
 }