RISC-V: Add zilsd & zclsd support

Ref: https://github.com/riscv/riscv-zilsd/blob/main/zilsd.adoc

Signed-off-by: dysun <sundongya@nucleisys.com>

Co-developed-by: LIU Xu <liuxu@nucleisys.com>
Co-developed-by: ZHAO Fujin <zhaofujin@nucleisys.com>

include/opcode/riscv.h

@@ -562,6 +562,8 @@ enum riscv_insn_class
   INSN_CLASS_ZCMP,
   INSN_CLASS_ZCMT,
   INSN_CLASS_SMCTR_OR_SSCTR,
+  INSN_CLASS_ZILSD,
+  INSN_CLASS_ZCLSD,
   INSN_CLASS_SMRNMI,
   INSN_CLASS_SVINVAL,
   INSN_CLASS_ZICBOM,