Use disassemble.c:disassembler select h8300 disassembler

Use disassemble.c:disassembler select h8300 disassembler

opcodes/disassble.c:disassembler select h8300 disassembler like this,

      if (mach == bfd_mach_h8300h || mach == bfd_mach_h8300hn)
	disassemble = print_insn_h8300h;
      else if (mach == bfd_mach_h8300s
	       || mach == bfd_mach_h8300sn
	       || mach == bfd_mach_h8300sx
	       || mach == bfd_mach_h8300sxn)
	disassemble = print_insn_h8300s;
      else
	disassemble = print_insn_h8300;

which is the same as what gdb/h8300-tdpe.c does,

  switch (info.bfd_arch_info->mach)
    {
    case bfd_mach_h8300:
    ...
      set_gdbarch_print_insn (gdbarch, print_insn_h8300);
    case bfd_mach_h8300h:
    case bfd_mach_h8300hn:
    ...
      set_gdbarch_print_insn (gdbarch, print_insn_h8300h);
    case bfd_mach_h8300s:
    case bfd_mach_h8300sn:
    ...
      set_gdbarch_print_insn (gdbarch, print_insn_h8300s);

so we can leave disassble.c:disassembler doing the selection.

gdb:

2017-05-24  Yao Qi  <yao.qi@linaro.org>

	* h8300-tdep.c (h8300_gdbarch_init): Don't call
	set_gdbarch_print_insn.