README update

[Roland McGrath]

All looks fine to me.  Just a couple of thoughts:

> +	powerpc-*-linux-gnu	Software floating point

Maybe:

	powerpc-*-linux-gnu	Software floating point (--without-fp)

>  The ports distribution also contains code for other configurations that
>  do not work or have not been maintained recently, but will be of use to

With your recent efforts to remove old stuff, perhaps this paragraph is no
longer true?


Thanks,
Roland