Correct the end address of the memory regions.

Pointed out by:	ian
Add support for empty ranges properties within the tree, some vendor
device trees have these, for example the ARM AArch64 Foundation Model.

Sponsored by:	The FreeBSD Foundation
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/segvguard