move some typedefs to procfs.h required by gdbserver build

Change-Id: I51fba4ceb80b63e583f462a2a00f3f658c7cdd36
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
diff --git a/libthread_db/include/thread_db.h b/libthread_db/include/thread_db.h
index 1b36cb2..6ff968f 100644
--- a/libthread_db/include/thread_db.h
+++ b/libthread_db/include/thread_db.h
@@ -9,9 +9,7 @@
 #include <signal.h>
 #include <stdint.h>
 #include <sys/types.h>
-
-typedef void *psaddr_t;
-typedef pid_t lwpid_t;
+#include <sys/procfs.h>
 
 #define TD_THR_ANY_USER_FLAGS       0xffffffff
 #define TD_THR_LOWEST_PRIORITY      -20