Improve ThunderX PEM driver to work on pass2 revision
Things changed: * do not allocate 4GB of SLI space, because it's the waste of system resources. Allocate only small portions when needed. * provide own implementation of activate_resource which performs address translation between PCI bus and host PA address space. This is temporary solution, should be replaced by bus_map_resource once implemented.
Obtained from: Semihalf
Sponsored by: Cavium
Approved by: cognet (mentor)
Reviewed by: jhb
Differential revision: https://reviews.freebsd.org/D5294