Fix microblaze sim build error

Fix microblaze sim build error

I see the following error for --target=microblaze-elf:

../../../sim/microblaze/interp.c: In function 'sim_engine_run':
../../../sim/microblaze/interp.c:147:39: error: passing argument 2 of 'get_insn_microblaze' from incompatible pointer type [-Werror=incompatible-pointer-types]
  147 |       op = get_insn_microblaze (inst, &imm_unsigned, &insn_type,
      |                                       ^~~~~~~~~~~~~
      |                                       |
      |                                       int *
In file included from ../../bfd/bfd.h:45,
                 from ../../../sim/microblaze/interp.c:24:
../../../sim/microblaze/../../opcodes/microblaze-dis.h:34:57: note: expected '_Bool *' but argument is of type 'int *'
   34 | extern enum microblaze_instr get_insn_microblaze (long, bool *,
      |                                                         ^

sim/microblaze/ChangeLog:

	* interp.c (sim_engine_run): Use bool instead of int.