Fix android build.

Change-Id: I094a80d0f4f12b6bdddf3709e30386738c853cac
diff --git a/libnos_transport/transport.c b/libnos_transport/transport.c
index 1e981ed..9c115d6 100644
--- a/libnos_transport/transport.c
+++ b/libnos_transport/transport.c
@@ -39,6 +39,8 @@
 #define NLOGV(...) do { if (VERBOSE_LOG) { ALOGV(__VA_ARGS__); } } while (0)
 #define NLOGD(...) do { if (DEBUG_LOG) { ALOGD(__VA_ARGS__); } } while (0)
 
+extern int usleep (uint32_t usec);
+
 #else
 /* Logging for other platforms */
 #include <stdio.h>