archs: replace unifdef-y with header-y

unifdef-y and header-y have same semantic, so drop unifdef-y

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index 63a2341..42e512b 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -1,15 +1,14 @@
 include include/asm-generic/Kbuild.asm
 
+header-y += chpid.h
+header-y += chsc.h
+header-y += cmb.h
 header-y += dasd.h
+header-y += debug.h
 header-y += monwriter.h
 header-y += qeth.h
+header-y += schid.h
 header-y += tape390.h
 header-y += ucontext.h
 header-y += vtoc.h
 header-y += zcrypt.h
-header-y += chsc.h
-
-unifdef-y += cmb.h
-unifdef-y += debug.h
-unifdef-y += chpid.h
-unifdef-y += schid.h