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>

Flush console where necessary ...

Call console_flush() before execution either terminates or leaves an
exception level.

Fixes: ARM-software/tf-issues#123

Change-Id: I64eeb92effb039f76937ce89f877b68e355588e3
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

FWU: Add Generic BL2U FWU image support in BL2 ...

The Firmware Update (FWU) feature needs support for an optional
secure world image, BL2U, to allow additional secure world
initialization required by FWU, for example DDR initialization.

This patch adds generic framework support to create BL2U.

NOTE: A platform makefile must supply additional `BL2U_SOURCES`
      to build the bl2u target. A subsequent patch adds bl2u
      support for ARM platforms.

Change-Id: If2ce036199bb40b39b7f91a9332106bcd4e25413