Revert "powerpc/p3060qds: Add support for P3060QDS board"

This reverts commit 96cc017c.

The P3060 was cancelled before it went into production, so there's no point
in supporting it.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>