powerpc: move include/asm-ppc64/ptrace-common.h to arch/powerpc/kernel

It's only used by arch/powerpc/kernel/ptrace{,32}.c.
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/ptrace.c

@@ -36,8 +36,9 @@
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
+
 #ifdef CONFIG_PPC64
-#include <asm/ptrace-common.h>
+#include "ptrace-common.h"
 #endif
 
 #ifdef CONFIG_PPC32

arch/powerpc/kernel/ptrace32.c

@@ -33,7 +33,8 @@
 #include <asm/page.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
-#include <asm/ptrace-common.h>
+
+#include "ptrace-common.h"
 
 /*
  * does not yet catch signals sent when the child dies.