Enable fingerprint checking as the currently known
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Approved by:	bapt
MFC after:	2 days
Use proper capitalization for FreeBSD.org

Approved by:	bapt
MFC after:	2 days
Call initarm_lastaddr() later in the init sequence, after establishing
static device mappings, rather than as the first of the initializations
that a platform can hook into.  This allows a platform to allocate KVA
from the top of the address space downwards for things like static device
mapping, and return the final "last usable address" result after that and
other early init work is done.

Because some platforms were doing work in initarm_lastaddr() that needs to
be done early, add a new initarm_early_init() routine and move the early
init code to that routine on those platforms.

Rename platform_devmap_init() to initarm_devmap_init() to match all the
other init routines called from initarm() that are designed to be
implemented by platform code.

Add a comment block that explains when these routines are called and the
type of work expected to be done in each of them.