[PATCH 10/31] FreeBSD OFED support for DPDK MLX5 PMD

Adding UIO driver that exposes the synthetic network device
resources to userspace for application such as DPDK can drive it.

Added rescind CB capability to the VMBUS driver. Whenever the
hypervisor wants to close the device channel, VMBUS on receiving
this msg, calls the CB of the device driver (hv_uio in our case).

Tested on KVM, ESXi, and HyperV/Azure Hypervisors with FreeBSD 14.0-CURRENT and FreeBSD12.1-STABLE.

iperf
DPDK MLX5 PMD/testpmd