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.

libsel4utils: Split up 'get_vspace_with_map'

Split up the functionality of 'sel4utils_get_vspace_with_map'
with the bootstrap intitialisation parts being moved into a
private helper function 'get_vspace_bootstrap'. This allows other
functions to modify specific fields in the
'sel4utils_alloc_data_t' token after it has been set to a default
state.

sel4utils: Mapping deferred rights reservations

Updated sel4utils to support the new vspace interface function:
'vspace_deferred_rights_map_pages_at_vaddr_fn'. This enables the
user to pass in the rights of the memory region when mapping a
'rights deferred' vspace reservation.

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'

utils: 0 pages in vspace bootstrap

SELFOUR-1296: Revert back to __executable_start

RISC-V port

SELFOUR-1053: Invoke VMM layer directly in vpsace_[new/map]_pages()

This change brings the behaviour of vspace_[new/map]_pages() in line with its
expected behaviour as the OS page-level combinatorial allocator -- such an
allocator is expected to directly call on the PMM and VMM for frames and pages
respectively, then map the frames into the pages, and do some book-keeping
before handing out the new vmem to userspace.

The previous implementation of vspace_[new/map]_pages had a call to
vspace_new_reservation which in turn had a call to malloc somewhere internally,
and this was causing a circular call path in our libraries.

Fix all the whitespace

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

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

libsel4utils: Use BYTES_TO_4K_PAGES correctly

libsel4utils: Reserve virtual addresses for extended bootinfo

libsel4utils: Remove some unnecessary type casts.

Remove all references to KERNEL_STABLE

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.

all: s/LOG_*/ZF_LOG*

libsel4utils: Avoid shadowing variables.

This change has no effect on functionality, but helps poor users such as myself
who switch on -Wshadow, only to be buffeted with spurious warnings.

libsel4utils: fix typos.

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