sim: info: convert verbose field to a bool

The verbose argument has always been an int treated as a bool, so
convert it to an explicit bool.  Further, update the API docs to
match the reality that the verbose value is actually used by some
of the internal modules.

sim/mcore/interp.c

@@ -1294,7 +1294,7 @@ mcore_reg_fetch (SIM_CPU *cpu, int rn, void *memory, int length)
 }
 
 void
-sim_info (SIM_DESC sd, int verbose)
+sim_info (SIM_DESC sd, bool verbose)
 {
   SIM_CPU *cpu = STATE_CPU (sd, 0);
   struct mcore_sim_cpu *mcore_cpu = MCORE_SIM_CPU (cpu);