s390/defconfig: add some NFT modules

Since Fedora 33 the virtualization stack of Fedora requires a couple of
netfilter modules to function properly. Let's add these to defconfig and
debug_defconfig.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Tested-by: Bjoern Walk <bwalk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>