sandybridge: Show spew raminit messages only with raminit debug

Change-Id: Ifbc59c28c8d8bd844801da9cb869c5dfbda09168
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/6754
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>