package/rdma-core: new package

This is the userspace components for the Linux Kernel's
drivers/infiniband subsystem.

https://github.com/linux-rdma/rdma-core



Tested-by: Shamraiz Ashraf <shamraizashraf092@gmail.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
[yann.morin.1998@free.fr:
  - select iproute2 as it provides the 'rdma' utility
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>