Update sel4platsupport_copy_irq_cap

- add sel4ps_irq_t which wraps ps_irq_t
- copy function now understands the type of irq and uses the correct
function from simple
- sel4platsupport_arch_copy_irq_cap deals with arch-specific
- removed
* sel4platsupport_copy_msi_cap
* sel4platsupport_copy_ioapic_cap

Fix all the whitespace

- remove trailing whitespace
- remove duplicate blank lines
- remove blank lines at end of files

Fix licenses

libsel4platsupport: Helper function for mapping in a physical address

libsel4platsupport: use HPET as default timer x86

This commit

* removes the legacy PIT as the default timer for x86,
replacing it with the HPET
* removes simple from the io mapper: this is a consequency of the
new device untyped feature in the kernel - device memory is now
allocated from the allocator, not simple, assuming that the
allocator has been given the relevant device memory (most sel4
apps immediately give all untypeds to the allocator)
* changes timer_common to allocate timer frames from the vka, not
simple (same reason as above)
* provides another method to initialise the HPET with a provided
physical address, such that a non-root task can be passed the
physical address and the corresponding untyped without needing to
parse acpi tables in order to find the HPET.

sel4simple: add arch specific interface

This commit defines arch_simple_t, which adds arch
specific functions to libsel4simple and its implementors,
as the seL4 API no longer allows simple implementation to be
architecture agnostic, specifically for the interrupt handling
interface.

This commit adds the x86 arch interface which defines functions
for getting irqs, msis and ioports, and the arm interface
which just defines irqs.

libsel4simple-stable has been updated to implement the new
interface and users should not be effected. However, other
implementations of simple will need to be updated.

libsel4platsupport has been updated such that the hpet driver
wrapper now works with the lastest seL4 kernel.

sel4utils: expose useful wrappers

Adds the following functions to the sel4platsupport api:

- sel4platsupport_copy_frame_cap
- sel4platsupport_copy_irq_cap

which both allocate a cslot and copy device caps to it from a simple
implementation.