[rtems] turn on part of unix directory

[Jeff Johnston]

Joel Sherrill wrote:
> Hi,
>
> Ralf is building RPMs with this now, so it is
> time to submit this.
>
> 2008-11-25  Joel Sherrill <joel.sherrill@oarcorp.com>
>
>    * configure.host (*-rtems*): Turn on using
>    portion of unix subdirectory.
>
Patch applied.

-- Jeff J.