Make kernel log buffer derived from cmake config

This removes the explicit CMake configuration for the kernel log buffer
and replaces it with a #define that is enabled for the required
configurations.

Signed-off-by: Curtis Millar <curtis@curtism.me>

replacing all ifndef with pargma once

All the kernel header files now use pargma once rather than the ifndef,
as the pre-processed C files do not change while header files
are protected with pargma once. This will also solve any naming issues
caused by ifndef.

Convert license tags to SPDX identifiers

This commit also converts our own copyright headers to directly use
SPDX, but leaves all other copyright header intact, only adding the
SPDX ident. As far as possible this commit also merges multiple
Data61 copyright statements/headers into one for consistency.

Replace IPC_BUF_GLOBALS_FRAME with KERNEL_GLOBALS_FRAME

The globals frame no longer serves its original purpose of informing a
thread of its IPC buffer address, and instead as a virtual
implementation of thread ID registers.

arm: Make Arm VCPU states per-node.

arm/hyp: add support for running multiple ARM VMs

This commit saves/restores various control registers that can be
modified by guest VM kernels, so seL4 can execute multiple ARM
32-bit VMs multiplexing a single physical core.

When the CONFIG_HAVE_FPU option is selected, the commit allows
the VMs to use FPU registers and enables lazily saving/restoring
FPU registers for the VMs.

arm_hyp: Use an explicitly invalid PD when there is no user one

When the user has no PD in order to schedule them we must still set something as
the active PD, just so that they can then fault. Previously when hypervisor was
enabled `0` was at as the PD. This worked as platforms typically do not have
anything valid, and certainly nothing resembling a page directory, at physical
address 0. This assumption is not very clean and unknown physical addresses
should not be accessed, so this change adds an explicit PD that is empty that
can be switched to.

ARM/SMP: Prepare for ARM SMP adding stubs

Currently building ARM/SMP is broken. This commit:
1- Makes it possible to build ARM/SMP with stubs. Run-time SMP for ARM
DOES NOT WORK.
2- Can be a reference for future SMP targets to follow in order to
layout/add the minimal required files and functions needed to support SMP.
3- Builds for Sabre only. In order to support other platforms, ipi
interrupt ID should be defined in machine.h

SMP: Abstract architecture/platform independent parts of smp.h and ipi.h

This commit is a re-arrangement of SMP directory structure to make it
easier for other architectures/platforms (in general) and ARM (in
particular) to add SMP support.

* new include/smp directory to act as a centralised container of
"shared" architecture-independent SMP headers.
This makes it clearer what's needed for other architecture/platform to
support SMP.
* Each platform can define its own unique ipi.[h|c] that make sense,
since ipi implementation is SoC/platform dependent.

SELFOUR-553: Support alternate IPC buffer locations without globals frame

This commit adds support for using the ThreadID registers of the ARM MPCore
platforms for storing the address of the IPC buffer instead of the globals
frame. The choice of using the user readable/writeable ThreadID register
is chosen, even though it means the user cannot use it for its own
purposes, as it leaves room in the future for doing TLS support in the
user read only register, where compilers expect it.

arm_hyp: Add lazy vcpu switching

arm_hyp: Declare armHSCurVCPU in header

arm_hyp: Move hype state into correct statedata header

The hypervisor state is declared in arch/32/statedata.c, but is
defined in arch/statedata.h. This commit moves the definitions to
arch/32/statedata.h to match all the other state in arch/32/statedata.c

SELFOUR-630:preliminary booting application processors
- update core detection code and Kconfig file
- update kernel stack managment so that BSP does not use boot stack before IPI APs
- move arch dependant data to a single structure
- add cache line size to Kconfig
- add cpu indexing and apic id mapping
- boot APs to halting state
- add guard for kernel stack if there is only one core

SELFOUR-556: Rationalize BITS vs INDEX_BITS

s/PD_BITS/PD_INDEX_BITS
Current convention is to say that X_BITS is the log base 2
size of an object, not the log base 2 number of indices

SELFOUR-556: Rationalize BITS vs INDEX_BITS

s/PT_BITS/PT_INDEX_BITS
Current convention is to say that X_BITS is the log base 2
size of an object, not the log base 2 number of indices

SELFOUR-518: User-level log buffer

Remove global ksLog and use KS_LOG_PPTR instead

Benchmark - Log buffer: use global page table

Rearranging headers for aarch32 to 32/mode/*