Valid addresses for GICR base are always a set calculable distance from
the GICD and is based on the number of cores a given instance of GICv3 IP
can support. The formula for the number of address bits is given by the
ARM GIC-500 TRM section 3.2 as 2^(18+log2(cores)) with the MSB set to
one for GICR instances. Holes in the GIC address space are also
guaranteed to safely return 0 on reads. This allows us to support runtime
detection of the GICR base address by starting from GIC base address plus
BIT(18) and walking until the GICR ID register (IIDR) is detected. We
stop searching after BIT(20) to prevent searching out into space if
something goes wrong. This can be extended out if we ever have a device
with 16 or more cores.

Signed-off-by: Andrew F. Davis <afd@ti.com>

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Do proper initialization of GIC V3. This will allow CP15 access to GIC
from "normal world" (aka HLOS) via mrc/mcr calls.

K3 SoC family uses GICv3 compliant GIC500 without compatibility for
legacy GICv2.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Benjamin Fair <b-fair@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>