Move remaining nptl_db headers to sysdeps/nptl

sys/procfs.h was already using this sysdeps directory.

This avoids the need for  nptl-specific wrapper headers under
include/, a generic location in the source tree.

ChangeLog

@@ -1,3 +1,11 @@
+2019-02-15  Florian Weimer  <fweimer@redhat.com>
+
+	* nptl_db/proc_service.h: Move to ...
+	* sysdeps/nptl/proc_service.h: ... here.
+	* nptl_db/thread_db.h: Move to ...
+	* sysdeps/nptl/thread_db.h: ... here.
+	* nptl/descr.h: Include <thread_db.h>.
+
 2019-02-15  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
 	* io/Makefile (tests): Add tst-lockf.

nptl/descr.h

@@ -29,7 +29,7 @@
 #include <lowlevellock.h>
 #include <pthreaddef.h>
 #include <dl-sysdep.h>
-#include "../nptl_db/thread_db.h"
+#include <thread_db.h>
 #include <tls.h>
 #include <unwind.h>
 #include <bits/types/res_state.h>