bsd-user: Add trace events for bsd-user

Add the bsd-user specific events and infrastructure. Only include the
linux-user trace events for linux-user, not bsd-user.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@freebsd.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/bsd-user/trace.h b/bsd-user/trace.h
new file mode 100644
index 0000000..593c020
--- /dev/null
+++ b/bsd-user/trace.h
@@ -0,0 +1 @@
+#include "trace/trace-bsd_user.h"