USB: gadget: Add HSUART transport for RMNET & DUN

HSUART transport can be used for communication
between MSM and MDM. Modify RMNET & DUN drivers to
support communication over HSUART transport.

CRs-Fixed: 355162
Change-Id: Idad2ab1b32d873cc055436537eed1715c92ceb90
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: Chiranjeevi Velempati <cvelempa@codeaurora.org>
4 files changed