powerpc arch now supported

We have added support for the powerpc arch branch in addition to the ppc arch branch.

The ppc branch is scheduled to be removed in June 2008. Thus, this change was needed to ensure the future development of Linux kernel patches for the Nintendo GameCube and Nintendo Wii.

The source code changes are already available through the project's cvs service at http://gc-linux.cvs.sourceforge.net/gc-linux/linux .