ipa disable pipes request is honoured based on
ipa_pipes_down flag. However, there is a possible
synchronization issue if disable pipes request is
initiated from different contexts, as there is no
locking to protect this flag.
Add pipes_down_in_progress flag in ipa_ctx and
use this flag to ignore disable pipes requests if
one request is already in progress.
Change-Id: Iabf01249d4b6a551e03cea2ae96a0c6096f43ff8
CRs-Fixed: 2423155
785b8450b5