kbuild: m68k,parisc,ppc,ppc64,s390,xtensa use generic asm-offsets.h support

Delete obsoleted parts form arch makefiles and rename to asm-offsets.h

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/s390/lib/uaccess64.S b/arch/s390/lib/uaccess64.S
index 0ca5697..5021978 100644
--- a/arch/s390/lib/uaccess64.S
+++ b/arch/s390/lib/uaccess64.S
@@ -11,7 +11,7 @@
 
 #include <linux/errno.h>
 #include <asm/lowcore.h>
-#include <asm/offsets.h>
+#include <asm/asm-offsets.h>
 
         .text
         .align 4