arm: Use little endian packet accessors.

We know data is little endian, so we can use those accessors
explicitly.

Change-Id: Iee337109fcda134e1ac5a700e5141fd7060f9c45
Reviewed-on: https://gem5-review.googlesource.com/c/13457
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

dev-arm: Fix the address range for some I/O devices

Previously, many devices were incorrecty configured to respond to an
address range of size 0xfff. This changes fixes this and sets it to
0x1000.

Change-Id: I4b027a27adf60ceae4859e287d7f34443b398752
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11116
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

style: [patch 1/22] use /r/3648/ to reorganize includes

mem: Remove redundant Packet::allocate calls

This patch cleans up the packet memory allocation confusion. The data
is always allocated at the requesting side, when a packet is created
(or copied), and there is never a need for any device to allocate any
space if it is merely responding to a paket. This behaviour is in line
with how SystemC and TLM works as well, thus increasing
interoperability, and matching established conventions.

The redundant calls to Packet::allocate are removed, and the checks in
the function are tightened up to make sure data is only ever allocated
once. There are still some oddities in the packet copy constructor
where we copy the data pointer if it is static (without ownership),
and allocate new space if the data is dynamic (with ownership). The
latter is being worked on further in a follow-on patch.

dev: make BasicPioDevice take size in constructor

Instead of relying on derived classes explicitly assigning
to the BasicPioDevice pioSize field, require them to pass
a size value in to the constructor.

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

dev/arm: get rid of AmbaDev namespace

It was confusing having an AmbaDev namespace along with an
AmbaDevice class. The namespace stuff is now moved in to
a new base AmbaDevice class, which is a mixin for classes
AmbaPioDevice (the former AmbaDevice) and AmbaDmaDevice
to provide the readId function as an inherited member function.

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

fix some build problems from prior changesets

ARM: Change how the AMBA device ID checking is done to make it more generic

ARM: Add I/O devices for booting linux