uboot-phytec

powerpc/mpc8xxx: check SPD length before using part number

Only use DDR DIMM part number if SPD has valid length, to prevent from
display garbage in case SPD doesn't cover these fields.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>