component/bt: build libbtdm_app.a with updated toolchain

diff --git a/components/bt/lib b/components/bt/lib
index cfff26955edbf837c497ef9d1dc60fc1e5a1608e..1b59f85d078347916d7f1271858cf29edf320f6d 160000 (submodule)
--- a/components/bt/lib
+++ b/components/bt/lib
@@ -1 +1 @@
-Subproject commit cfff26955edbf837c497ef9d1dc60fc1e5a1608e
+Subproject commit 1b59f85d078347916d7f1271858cf29edf320f6d