Merge branch 'erdma' into rdma.git for-next

Cheng Xu says

====================
This v14 patch set introduces the Elastic RDMA Adapter (ERDMA) driver,
which released in Apsara Conference 2021 by Alibaba. The PR of ERDMA
userspace provider has already been created [1].

ERDMA enables large-scale RDMA acceleration capability in Alibaba ECS
environment, initially offered in g7re instance. It can improve the
efficiency of large-scale distributed computing and communication
significantly and expand dynamically with the cluster scale of Alibaba
Cloud.

ERDMA is a RDMA networking adapter based on the Alibaba MOC hardware. It
works in the VPC network environment (overlay network), and uses iWarp
transport protocol. ERDMA supports reliable connection (RC). ERDMA also
supports both kernel space and user space verbs. Now we have already
supported HPC/AI applications with libfabric, NoF and some other internal
verbs libraries, such as xrdma, epsl, etc,.

For the ECS instance with RDMA enabled, our MOC hardware generates two
kinds of PCI devices: one for ERDMA, and one for the original net device
(virtio-net). They are separated PCI devices.
====================

* branch 'erdma':
  RDMA/erdma: Add driver to kernel build environment
  RDMA/erdma: Add the ABI definitions
  RDMA/erdma: Add the erdma module
  RDMA/erdma: Add connection management (CM) support
  RDMA/erdma: Add verbs implementation
  RDMA/erdma: Add verbs header file
  RDMA/erdma: Add event queue implementation
  RDMA/erdma: Add cmdq implementation
  RDMA/erdma: Add main include file
  RDMA/erdma: Add the hardware related definitions
  RDMA: Add ERDMA to rdma_driver_id definition

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>