ice(4): Add RDMA Client Interface

This allows the "irdma" driver to communicate with the ice(4)
driver to allow it access to the underlying device's hardware
resources as well as synchronize access to shared resources.

This interface already existed in the standalone out-of-tree
1.34.2 driver; this commit adds and enables it in the in-kernel
driver.

Note:

Adds hack to module Makefile to compile interface/.m files

These are required for the RDMA client interface, but they don't
build as-is like the normal .c files. The source directory doesn't
seem to be included by default, so add lines that specifically
add them as libraries so that ice_rdma.h can be found and the
interface files will compile.

Signed-off-by: Eric Joyner <erj@FreeBSD.org>

Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D30889

(cherry picked from commit 8a13362d49bf07dfc654e25976d057adbe0ac9c1)
(cherry picked from commit d8cce8145c39812cc31b50070c44d66ca21a5127)