Convert to SPDX license tags

Signed-off-by: Gerwin Klein <gerwin.klein@data61.csiro.au>

trivial: update tk1 header guard

Signed-off-by: Oliver Scott <Oliver.Scott@data61.csiro.au>

libsel4vm: Styled src/guest_vspace.c

Updated style of `src/guest_vspace.c`

libsel4vm: Pass vm handle to vm_guest_add_iospace

Updated the parameters to the interface function
'vm_guest_add_iospace'. This change substitutes the vspace
parameter with the VM object. This allows us to abstract the
internals of the VM datastructure making the interface easier to
use.

libsel4vm*: Switch malloc calls to calloc

Reduces chances of an uninitialised structure being used and causing
issues that are painful to debug.

libsel4vm: Updated use of 'get_vspace' function

We now use the new libsel4util function
'sel4utils_get_empty_vspace_with_map'. This ensures we create a
vspace with no kernel reservations.

libsel4vm: Refactored iospace interface

Made 'vm_guest_add_iospace' within the guest_vspace implementation
a public interface. In addition, removed and re-adjusted the
io config options (e,g, CONFIG_ARM_SMMU, CONFIG_IOMMU) such that
only guards code that performs vspace mappings.

libsel4vm: Made guest_vspace interface private

Refactored the guest_vspace source to be private. This in
particular makes 'vm_init_guest_vspace' a private function
(named 'vm_get_guest_vspace' prior).

libsel4vm: Removed translation_vspace tracking

As guest_vspace_touch has been removed from the guest_vspace
interface, we no longer need to maintain vm->vmm mappings. Removed
the usages of translation_vspace from guest_vspace.

libsel4vm: Refactored guest_vspace_touch

Removed vm_guest_vspace_touch out of the guest_vspace. This has
been reimplemented in a new interface, being 'guest_memory.h'.
Now called 'vm_guest_mem_touch'. Rather than relying on an
internal vm->vmm translation mechanism, vm_guest_mem_touch uses
the vspace interface 'vspace_access_page_with_callback' to
perform page accesses.

libsel4vm: iospaces dynamically allocated

Updated guest_vspace to maintain a set of iospace pointers that
are dynamically when iospaces are added to the vm.

libsel4vm: Consolidated guest vspace source

The guest vspace management existed in both the x86 and arm
vmm implementation. This commit creates a consolidated guest vspace
management interface, refactoring the implementations that existed
in sel4-arm-vmm and sel4-x86-vmm.