ARMv7: Rationalised coreboot structures.

Put the Multiboot header in the coredata struct, and allocate both in and the
globals (which now contains only the printf spinlock) in the BSP kernel's BSS.
We no longer rely on magic addresses.

Doing so exposed a latent bug, where code using the various alloc_phys()
functions were assuming that the output would be page-aligned, when that
wasn't guaranteed. Added alloc_phys_aligned to all relevant prototypes.

Signed-off-by: David Cock <david.cock@inf.ethz.ch>

Clean merge of HP's ARMv8 code

This adds support for an ARMv8 core running in the GEM5 simulator

Signed-off-by: David Cock <david.cock@inf.ethz.ch>

arm_molly: reformatted and squashed build errors.

arm_molly: reformatted and squashed build errors.

basic armv7-m support

added new hake architecture "armv7-m"
added armv7-m port of kernel and libbarrelfish
fixed small arm_molly issues with parsing paths containing '-'

the port does not actually handle interrupts yet, but scheduling, spawning, and starting processes works
this update does not yet contain the armv7-a code to start the m3 core

added new machine gem5.py to scalebench

Fix several bugs in GEM5 molly. Most important is to zero the static
data structures, which are not zeroed on real hardware.

large part of arm gem5 port rewritten, now support multiboot bootloader and dynamic kernel relocation, added a loader for gem5 to mimick a multiboot bootloader