powerpc/86xx: Renaming following split of GE Fanuc joint venture

This patch renames GE Fanuc boards following the split-up of the GE Fanuc
joint venture. These boards are now made by GE Intelligent platorms.

Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>