Improve Core Selection in SBE Update code
Improve Core Selection in SBE Update code

This code improves how cores are selected in the case that the
p8_xip_customize() procedure can't fit certain cores into the
custom SBE image.  The fix ensures that 'good' cores are always
used when possible.

Change-Id: Idf606dca9316879f5aae4c728b582de628a54667
RTC: 98673
Backport: release-fips810
CQ: SW253657
Reviewed-on: http://gfw160.aus.stglabs.ibm.com:8080/gerrit/9842
Tested-by: Jenkins Server
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>
Reviewed-by: A. Patrick Williams III <c87e37b1a4035affd737b461af89fb722d635f4d@us.ibm.com>

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