clean up

incl/iss/arch/tgc_c.h

@@ -258,7 +258,6 @@ struct tgc_c: public arch_if {
         uint32_t DPC = 0;
         uint32_t trap_state = 0, pending_trap = 0;
         uint64_t icount = 0;
-        uint64_t cycle = 0;
         uint64_t instret = 0;
         uint32_t last_branch;
     } reg;