Huawei BMA: Adding Huawei BMA driver: cdev_veth_drv

driver inclusion
category: feature
bugzilla: 34535
CVE: NA

The BMA software is a system management software offered by Huawei. It supports
the status monitoring, performance monitoring, and event monitoring of various
components, including server CPUs, memory, hard disks, NICs, IB cards, PCIe
cards, RAID controller cards, and optical modules.

This cdev_veth_drv driver is one of the communication drivers used by BMA
software. It depends on the host_edma_drv driver. It will create a char device
once loaded, offering interfaces (open, close, read, write and poll) to BMA to
send/receive RESTful messages between BMC software. When the message is longer
than 1KB, it will be cut into packets of 1KB. The other side, BMC's cdev_veth
driver, will assemble these packets back into original mesages.

Link: https://lkml.org/lkml/2020/6/22/752


Signed-off-by: Naixin Yu <yunaixin@huawei.com>
Reviewed-by: Wang Qindong <wangqindong@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Cheng Jian <cj.chengjian@huawei.com>