[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: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kbuild

-obj-y += kernel/
-obj-y += mm/
-obj-y += crypto/
-obj-y += appldata/
-obj-y += hypfs/
-obj-y += kvm/
+obj-y				+= kernel/
+obj-y				+= mm/
+obj-$(CONFIG_KVM)		+= kvm/
+obj-$(CONFIG_CRYPTO_HW)		+= crypto/
+obj-$(CONFIG_S390_HYPFS_FS)	+= hypfs/
+obj-$(CONFIG_APPLDATA_BASE)	+= appldata/
+obj-$(CONFIG_MATHEMU)		+= math-emu/

arch/s390/Makefile

@@ -99,7 +99,6 @@ core-y		+= arch/s390/
 
 libs-y		+= arch/s390/lib/
 drivers-y	+= drivers/s390/
-drivers-$(CONFIG_MATHEMU) += arch/s390/math-emu/
 
 # must be linked after kernel
 drivers-$(CONFIG_OPROFILE)	+= arch/s390/oprofile/