MFC: r291121

MFC: r291121

Merge from r290547:
Since r289279 bufinit() uses mp_ncpus so adapt to what x86 does and
set this variable already in cpu_mp_setmaxid().
While at it, rename cpu_cpuid_prop() to cpu_portid_prop() as well as
the MD cpuid variable to portid to avoid confusion with the MI use
of "cpuid" and make some variable static/global in order to reduce
stack usage.

PR:		204685

git-svn-id: svn://svn.freebsd.org/base/stable/10@292771 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f