msm: ipa: Add support for WAN Transport Driver

The WAN Transport driver implements network stack
class device. It supports following functionalities.
- Embedded data transfer from A7 to Q6
- Configures IPA HW for RmNet Data Driver
- Exchange of QMI messages between A7 and Q6 IPA-driver

Change-Id: I8568b5fc4aad186557ac3e32989b5a9c382ccb66
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>