MSM MHI RMNET interface device

MHI RMNET provides a network interface over PCIe to transfer IP packets
between modem and apps.

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Node Structure
==============

Main node properties:

- compatible
  Usage: required
  Value type: <string>
  Definition: "qcom,mhi-rmnet"

- qcom,mhi-rx-channel
  Usage: optional if mhi-tx-channel is defined.
  Value type: <u32>
  Definition: MHI channel number for incoming data

- qcom,mhi-tx-channel
  Usage: optional if mhi-rx-channel is defined.
  Value type: <u32>
  Definition: MHI channel number for outgoing data

- qcom,mhi-mru
  Usage: required
  Value type: <u32>
  Definition: Default payload size for receive path.

- qcom,mhi-max-mru
  Usage: optional
  Value type: <u32>
  Definition: Maximum payload interface support on receive path.  If
	not defined MHI_MAX_MRU is used.

- qcom,mhi-max-mtu
  Usage: optional
  Value type: <u32>
  Definition: Maximum payload interface support on transmit path.  If
	not defined MHI_MAX_MTU is used.

- qcom,interface-name
  Usage: optional
  Value type: <string>
  Definition: optional string to overwrite default interface name. If
	not defined string RMNET_MHI_DRIVER_NAME is used.

========
Example:
========
mhi_rmnet_0: qcom,mhi-rmnet@0 {
	compatible = "qcom,mhi-rmnet";
	qcom,mhi-rx-channel = <101>;
	qcom,mhi-tx-channel = <100>;
	qcom,mhi-mru = <8000>;
	status = "okay";
};