msm: ipa: create ipa_client for ethernet

Create the ipa_client interface for ethernet offloading.

Change-Id: I8120b0cca9e42a75153fb1468dc1b8bcbd43484c
Signed-off-by: Bojun Pan <bojunp@codeaurora.org>
Signed-off-by: Amir Levy <alevy@codeaurora.org>