[S390] make arch/s390 subdirectories depend on config option

Only add subdirectories of arch/s390 to kbuild if their respective
config option is selected.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2 files changed