Fixes [BUGID #500]
While the tuning for the mpc8315e is 603e, the PACKAGE_EXTRA_ARCHES
was ppce300. This created a mismatch and resulted in rootfs assembly
issues due to missing locales.
We align both at 603 and can revist a better tuning in the future.
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>