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>

Move plat/common source file definitions to generic Makefiles ...

These source file definitions should be defined in generic
Makefiles so that all platforms can benefit. Ensure that the
symbols are properly marked as weak so they can be overridden
by platforms.

NOTE: This change is a potential compatibility break for
non-upstream platforms.

Change-Id: I7b892efa9f2d6d216931360dc6c436e1d10cffed
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Migrate platform makefile to new console driver location ...

This patch migrates the upstream platform makefiles to include the
console drivers from the new location in ARM Trusted Firmware code
base.

Change-Id: I866d6c4951e475de1f836ce8a8c1d5e6da9577e3

Add support for QEMU virt ARMv8-A target ...

This patch adds support for the QEMU virt ARMv8-A target.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>