[S390] remove DEFAULT_MIGRATION_COST

0437e109e1841607f2988891eaa36c531c6aa6ac removes the migration
cost init code. Remove the s390 leftovers as well.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 file changed