msm: ipa: add API to configure holb

Clients can now configure head-of-line-blocking behavior
for their end-points.

Change-Id: I730ab08d0aadad9224a8aa55cf79a9881f1ab219
Signed-off-by: Ravi Gummadidala <rgummadi@codeaurora.org>
Signed-off-by: Vladislav Mordohovich <vmordoho@codeaurora.org>