Fix `Make dist-srpm` issue with CONFIG_VDPA
when building SRPMS the following mismatch is reported
Processing ./redhat/configs/kernel-s390x-zfcpdump-rhel.config ... Error: Mismatches found in configuration files Found CONFIG_VDPA=y after generation, had CONFIG_VDPA=m in Source tree
This Commit sets CONFIG_VDPA=y on zfcpdump s390x