configure: fix S390X CPUNAME:
configure: fix S390X CPUNAME:

The value was changed to S390x, presumably by accident, breaking the
build (regression from 480b32d3809830002ecc28508d40af3ecd4ad272).

Change-Id: Icca90818c6363855437a273714a8317becdfd0e5

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core