nehalem sandy ivy: Check cbmem_add() result for MRC data

In theory we could run out of CBMEM space so check the entry was added.
There is no interest to support builds without EARLY_CBMEM_INIT.

Change-Id: I68dd7c20e3d3692331aaafa2a692c5c0dfce95d5
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/6033
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>
2 files changed