msm:ipa: stop UL IPA TX channel at the end of the probe

Stop UL MHIP IPA TX channel at end of the probe
if there is no active tethering. This will make sure no Uplink data is
sent when Device side is not prepared to take data.

Change-Id: Id37c0c7eb8270bdf4806265c75780951ae7394c3
Signed-off-by: Michael Adisumarta <madisuma@codeaurora.org>