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>

Many asserts depend on code that is conditionally compiled based on the
DEBUG define. This patch modifies the conditional inclusion of such code
so that it is based on the ENABLE_ASSERTIONS build option.

Change-Id: I6406674788aa7e1ad7c23d86ce94482ad3c382bd
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

C files shouldn't be included into others. This file only contains some
macros and functions that can be made `static inline`, so it is ok to
convert it into a header file.

This is the only occurrence of a C file being included in another one in
the codebase instead of using a header, other occurrences are a way of
achieving backwards-compatibility.

Functions therein have been qualified as `inline`.

Change-Id: I88fe300f6d85a7f0740ef14c9cb8fa54849218e6
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>