ruby: Add support for address ranges in the directory

Previously the directory covered a flat address range that always
started from address 0. This change adds a vector of address ranges
with interleaving and hashing that each directory keeps track of and
the necessary flexibility to support systems with non continuous
memory ranges.

Change-Id: I6ea1c629bdf4c5137b7d9c89dbaf6c826adfd977
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2903
Reviewed-by: Bradford Beckmann <brad.beckmann@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

ruby: fix MOESI_hammer directory to work with > 3GB memory

The MOESI_hammer directory assumes a contiguous address space, but X86
has an IO gap from 3-4GB. This patch allows the directory to work with
more than 3GB of memory on X86.

Assumptions: the physical address space (range of possible physical
addresses) is 0-XGB when X <= 3GB, and 0-(X+1)GB when X > 3GB. If there
is no IO gap this patch should still work.

Change-Id: I5453a09e953643cada2c096a91d339a3676f55ee
Reviewed-on: https://gem5-review.googlesource.com/2169
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>

ruby: interface with classic memory controller
This patch is the final in the series. The whole series and this patch in
particular were written with the aim of interfacing ruby's directory controller
with the memory controller in the classic memory system. This is being done
since ruby's memory controller has not being kept up to date with the changes
going on in DRAMs. Classic's memory controller is more up to date and
supports multiple different types of DRAM. This also brings classic and
ruby ever more close. The patch also changes ruby's memory controller to
expose the same interface.

ruby: move files from ruby/system to ruby/structures

The directory ruby/system is crowded and unorganized. Hence, the files the
hold actual physical structures, are being moved to the directory
ruby/structures. This includes Cache Memory, Directory Memory,
Memory Controller, Wire Buffer, TBE Table, Perfect Cache Memory, Timer Table,
Bank Array.

The directory ruby/systems has the glue code that holds these structures
together.