The only difference between GIC-500 and GIC-600 relevant to TF-A is the
differing power management sequence.
A certain GIC implementation is detectable at runtime, for instance by
checking the IIDR register. Let's add that test before initiating the
GIC-600 specific sequence, so the code can be used on both GIC-600 and
GIC-500 chips alike, without deciding on a GIC chip at compile time.

This means that the GIC-500 "driver" is now redundant. To allow minimal
platform support, add a switch to disable GIC-600 support.

Change-Id: I17ea97d9fb05874772ebaa13e6678b4ba3415557
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

This patch adds support for Total Compute (TC0) platform. It is an
initial port and additional features are expected to be added later.

TC0 has a SCP which brings the primary Cortex-A out of reset
which starts executing BL1. TF-A optionally authenticates the SCP
ram-fw available in FIP and makes it available for SCP to copy.

Some of the major features included and tested in this platform
port include TBBR, PSCI, MHUv2 and DVFS.

Change-Id: I1675e9d200ca7687c215009eef483d9b3ee764ef
Signed-off-by: Usama Arif <usama.arif@arm.com>