This commit adds support for registering MHI client drivers with the
MHI stack. MHI client drivers binds to one or more MHI devices inorder
to sends and receive the upper-layer protocol packets like IP packets,
modem control messages, and diagnostics messages over MHI bus.
This is based on the patch submitted by Sujeev Dias:
https://lkml.org/lkml/2018/7/9/987
Signed-off-by: Sujeev Dias <sdias@xxxxxxxxxxxxxx>
Signed-off-by: Siddartha Mohanadoss <smohanad@xxxxxxxxxxxxxx>
[mani: splitted and cleaned up for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>