[RISCV][NFC] Remove Redundant Inline Asm Logic (#124202)

This was left over from 408659c.

Author: lenary

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -21133,8 +21133,6 @@ RISCVTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
       }
       break;
     case 'R':
-      if (VT == MVT::f64 && !Subtarget.is64Bit() && Subtarget.hasStdExtZdinx())
-        return std::make_pair(0U, &RISCV::GPRPairNoX0RegClass);
       return std::make_pair(0U, &RISCV::GPRPairNoX0RegClass);
     default:
       break;