huawei: delay processing of network-initiated disconnection

Originally developed by:
  Prathmesh Prabhu <pprabhu@chromium.org>
  Ben Chan <benchan@chromium.org>

Huawei MU736 prematurely fires a ^NDISSTAT unsolicited message upon a
network-initiated disconnection. The modem can go into a bad state if a
reconnect attempt happens before the disconnection completes. This patch works
around the issue by delaying the reporting of the disconnection.

(cherry picked from commit 21a5aaf4fe6934aad2e6c770aa4bdffa3ad29f9d)
3 files changed