ATTN: Partially fix shutdown / EOI race.
ATTN: Partially fix shutdown / EOI race.

Change-Id: Id43f747bb5cb84cbe7cc13d4a8ed15a9d9e4fadf
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/2972
Tested-by: Jenkins Server
Reviewed-by: Brian J. Stegmiller <4c05ea37f9d6efb9a2c94995009b8b66580a4c01@us.ibm.com>
Reviewed-by: Zane Shelley <fc96e127d170d6ac0b2af86a8a56f95974ff36e8@us.ibm.com>
Reviewed-by: A. Patrick Williams III <c87e37b1a4035affd737b461af89fb722d635f4d@us.ibm.com>

open-power/hostboot,open-power/hostboot,csmart/hostboot,open-power/hostboot,Over-enthusiastic/hostboot,alvintpwang/hostboot,csmart/hostboot,open-power/hostboot,csmart/hostboot,alvintpwang/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,csmart/hostboot,alvintpwang/hostboot,alvintpwang/hostboot,csmart/hostboot,alvintpwang/hostboot,open-power/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot