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/ppc/kernel/head_4xx.S b/arch/ppc/kernel/head_4xx.S
index ca9518b..8562b80 100644
--- a/arch/ppc/kernel/head_4xx.S
+++ b/arch/ppc/kernel/head_4xx.S
@@ -40,7 +40,7 @@
 #include <asm/cputable.h>
 #include <asm/thread_info.h>
 #include <asm/ppc_asm.h>
-#include <asm/offsets.h>
+#include <asm/asm-offsets.h>
 
 /* As with the other PowerPC ports, it is expected that when code
  * execution begins here, the following registers contain valid, yet