msm: ipa4: add generic header processing context

IPA uC now supports generic header processing context that
accepts source and target headers negative offset as parameters.
This change adds HAL and API support for this new feature.

Change-Id: Idb4c977f55175a66b55b92225f6677431ad8066a
Signed-off-by: Amir Levy <alevy@codeaurora.org>