arm: Remove unused DumpStatsPCEventF class in FreeBSD system

The DumpStatsPCEventF is declared but lacks an implementation. This
confuses RTTI in clang. Remove this class since it is clearly not
needed.

Change-Id: Ib95f09f2ba8593f8d0e072b96afd5f8a9ed31070
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3240
Reviewed-by: B.A. Zeeb <baz21@cam.ac.uk>

arm: Remove unnecessary boot uncachability

With the recent patches addressing how we deal with uncacheable
accesses there is no longer need for the work arounds put in place to
enforce certain sections of memory to be uncacheable during boot.

arch, base, dev, kern, sym: FreeBSD support

This adds support for FreeBSD/aarch64 FS and SE mode (basic set of syscalls only)

Committed by: Nilay Vaish <nilay@cs.wisc.edu>