Use SPDX license identifiers ...

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

fiptool: Remove unreferenced variable `toc_entries_len` ...

Change-Id: If279680a71e7fa1f801d79b8bc2cd47cd9905d33
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

fiptool: Prepare ground for expanding the set of images at runtime ...

To allow operating on images with unknown UUIDs, fiptool needs to
be able to track an arbitrary amount of images and not be limited
to the set of images described by the builtin table.

Convert the table to a list to accommodate this scenario.

Change-Id: I0e6d738eece7795d74fc72d165a3098f223d4414
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

fiptool: Link `toc_entry` and `image` structures via UUID ...

The `toc_entry` and `image` data structures had a cyclic
relationship.  This patch removes the explicit dependencies and introduces
functions to link them via the UUID.

This change highlights the intent of the code better and makes it more
flexible for future enhancements.

Change-Id: I0c3dd7bfda2a631a3827c8ba4831849c500affe9
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Replace fip_create with fiptool ...

fiptool provides a more consistent and intuitive interface compared to
the fip_create program.  It serves as a better base to build on more
features in the future.

fiptool supports various subcommands.  Below are the currently
supported subcommands:

1) info   - List the images contained in a FIP file.
2) create - Create a new FIP file with the given images.
3) update - Update an existing FIP with the given images.
4) unpack - Extract a selected set or all the images from a FIP file.
5) remove - Remove images from a FIP file.  This is a new command that
   was not present in fip_create.

To create a new FIP file, replace "fip_create" with "fiptool create".

To update a FIP file, replace "fip_create" with "fiptool update".

To dump the contents of a FIP file, replace "fip_create --dump" with
"fiptool info".

A compatibility script that emulates the basic functionality of
fip_create is provided.  Existing scripts might or might not work with
the compatibility script.  Users are strongly encouraged to migrate to
fiptool.

Fixes ARM-Software/tf-issues#87
Fixes ARM-Software/tf-issues#108
Fixes ARM-Software/tf-issues#361

Change-Id: I7ee4da7ac60179cc83cf46af890fd8bc61a53330