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/include/asm-xtensa/ptrace.h b/include/asm-xtensa/ptrace.h
index 2848a5f..aa4fd7f 100644
--- a/include/asm-xtensa/ptrace.h
+++ b/include/asm-xtensa/ptrace.h
@@ -127,7 +127,7 @@
 #else	/* __ASSEMBLY__ */
 
 #ifdef __KERNEL__
-# include <asm/offsets.h>
+# include <asm/asm-offsets.h>
 #define PT_REGS_OFFSET	  (KERNEL_STACK_SIZE - PT_USER_SIZE)
 #endif