Eliminate an unused macro whose name clashes now with a function in the
new cpu-v6.h.  This should have been part of r276334.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@276335 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Add cache maintenance functions which will be used by startup code to
initially set up the MMU.  Some day they may also be useful as part of
suspend/resume handling, when we get better at power management.

Submitted by: Svatopluk Kraus <onwahe@gmail.com>,
              Michal Meloun <meloun@miracle.cz


git-svn-id: svn+ssh://svn.freebsd.org/base/head@276336 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f