irdma: fix LINT-NOIP/NOINET/NOINET6 builds

This module depends on the presence of both INET and INET6 options in
order to compile.

Reviewed by: erj
Fixes: cdcd52d41e24 ("irdma: Add RDMA driver for Intel(R) Ethernet...")
Approved by: re (cperciva)
Differential Revision: https://reviews.freebsd.org/D35343

(cherry picked from commit acdfbc6cbe0a8a976d446216be84994c8ee8d5c1)
(cherry picked from commit 7333d34e5ec96db747648ab7b245d814d3140738)