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/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index ee58d37..be0f07f 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -23,7 +23,7 @@
  */
 
 #include <linux/config.h>
-#include <asm/offsets.h>
+#include <asm/asm-offsets.h>
 
 /* we have the following possibilities to act on an interruption:
  *  - handle in assembly and use shadowed registers only