qemu: fix holding pen mailbox sequence ...

Before this change, plat_secondary_cold_boot_setup reads wake up mailbox
as a byte array but through 64bit accesses on unaligned 64bit addresses.
In the other hand qemu_pwr_domain_on wakes secondary cores by writing
into a 64bit array.

This change forces the 64bit mailbox format as PLAT_QEMU_HOLD_ENTRY_SIZE
explicitly specifies it.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

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>

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>