um: Don't pollute kernel namespace with uapi

Don't include ptrace uapi stuff in arch headers, it will
pollute the kernel namespace and conflict with existing
stuff.
In this case it fixes clashes with common names like R8.

Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c
index cac2ea0..6a826cb 100644
--- a/arch/um/kernel/ptrace.c
+++ b/arch/um/kernel/ptrace.c
@@ -8,6 +8,7 @@
 #include <linux/sched.h>
 #include <linux/tracehook.h>
 #include <asm/uaccess.h>
+#include <asm/ptrace-abi.h>
 
 void user_enable_single_step(struct task_struct *child)
 {