[GOLD] Add --secure-plt option for ppc32

[Cary Coutant]

>> > +  DEFINE_bool(secure_plt, options::TWO_DASHES , '\0', true,
>> > +             N_("(PowerPC only) Use new-style PLT.  (default and forced)"),
>> > +             NULL);
>>
>> Gold's --help will now print "(default)" automatically for this
>> option, so it's redundant here. What do you mean by "forced"?
>
> Oops, didn't even look at the help output.  By forced I meant that
> there is no --no-secure-plt (or --bss-plt) but saying that isn't
> necessary.  Will remove it and the unnecessary "default".

OK with that change.

-cary