libsel4utils: Initialise an empty vspace

Implemented a new interface function
'sel4utils_get_empty_vspace' that allows the user to
create a vspace that has no part of the virtual address
space being pre-reserved e.g. kernel region. This is useful in
cases where processes belong to virtual machine based applications
and need the full address space.

libsel4utils: Initialise an empty vspace

Implemented a new interface function
'sel4utils_get_empty_vspace_with_map' that allows the user to
create a vspace (with map) that has no part of the virtual address
space being pre-reserved e.g. kernel region. This is useful in
cases where processes belong to virtual machine based applications
and need the full address space.

sel4utils: Deferred rights reservation creation

Updated sel4utils to support the new vspace interface function:
'vspace_reserve_deferred_rights_range_at_fn'. This enables the
user to create vspace reservations without passing the rights of
the memory region. The rights being deferred to the mapping
invocation.

Trivial: Style fix

make the style checker happy

seL4_libs: remove autoconf.h from seL4_libs

this commit removes autoconf.h generation from each lib and
append '#include <<lib_name>/gen_config.h>' after each
'#include <autoconf.h>' since autoconf.h is only the for the
kernel config now. This is a temporarily solution, since we
currently don't have a way to tell which header files each file
is trying to include when it includes 'autoconf.h'

sel4utils: use seL4_UserTop

This commit removes hard coded KERNEL_RESERVED_START values (which is
mean to represent the last page mappable by user-level) and calculates
the value from seL4_UserTop instead, such that if seL4_UserTop changes
at any point the vspace code will still work.

SELFOUR-1283: Include arch vspace.h from top level

pragma once and for all

Fix licenses

Remove #ifdef guards for the existance of different libraries

These libraries are now all part of this same repository, and so they will always exist.
Guarding for them adds unnecessary complexity

SELFOUR-567: use seL4_CapRights_t

sel4utils: add vspace_get_paddr

sel4utils: fix minor typo that causes compilation error

sel4utils: change sel4utils_get_image_region() declaration to match its definition

libsel4utils: Rewrite vspace for 64bit support

This involves a nearly full rewrite of the internals of the vspace
implementation. The core reason for the rewrite was to go from a
fixed two level book keeping structure, to a multi level book
keeping structure.

libsel4utils: fix typos.

libsel4utils: remove sel4utils_free_reservation_no_alloc (use
sel4utils_free_reservation) and fix memory leaks.

libsel4vspace/utils: use uinptr_t instead of doing undefined void * arithmetic