common: Drop asm/ptrace.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/cpu/mpc83xx/traps.c b/arch/powerpc/cpu/mpc83xx/traps.c
index 1c6c38b..c3cc119 100644
--- a/arch/powerpc/cpu/mpc83xx/traps.c
+++ b/arch/powerpc/cpu/mpc83xx/traps.c
@@ -12,6 +12,7 @@
  */
 
 #include <common.h>
+#include <asm/ptrace.h>
 #include <command.h>
 #include <kgdb.h>
 #include <asm/processor.h>