Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928d5b7 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3a282 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca33988b9 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

On SGI platforms, the interconnect is setup by the SCP and so the
existing unused interconnect setup in sgi575 platform code can be
removed. As a result of this, sgi_plat_config.c and sgi_bl1_setup.c
files can be removed as these files are now empty or can be
substainated by the existing weak functions.

Change-Id: I3c883e4d1959d890bf2213a9be01f02551ea3a45
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>

Mark the initialization functions found in the BL31 boot sequence
as __init so they can be reclaimed when no longer needed.

Change-Id: I687a89346419c7710ef5097feaa325d83c527697
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>

Add support for System Guidance for Infrastructure platform SGI575.

Change-Id: I0125c2ed4469fbc8367dafcc8adce770b6b3147d
Signed-off-by: Nariman Poushin <nariman.poushin@linaro.org>