arm64: dts: ti: k3-am64: Fix gic-v3 compatible regs

arm64: dts: ti: k3-am64: Fix gic-v3 compatible regs

Though GIC ARE option is disabled for no GIC-v2 compatibility,
Cortex-A53 is free to implement the CPU interface as long as it
communicates with the GIC using the stream protocol. This requires
that the SoC integration mark out the PERIPHBASE[1] as reserved area
within the SoC. See longer discussion in [2] for further information.

Update the GIC register map to indicate offsets from PERIPHBASE based
on [3]. Without doing this, systems like kvm will not function with
gic-v2 emulation.

[1] https://developer.arm.com/documentation/ddi0500/e/system-control/aarch64-register-descriptions/configuration-base-address-register--el1
[2] https://lore.kernel.org/all/87k0e0tirw.wl-maz@kernel.org/
[3] https://developer.arm.com/documentation/ddi0500/e/generic-interrupt-controller-cpu-interface/gic-programmers-model/memory-map

Cc: stable@vger.kernel.org
Fixes: 8abae9389bdb ("arm64: dts: ti: Add support for AM642 SoC")
Reported-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220215201008.15235-5-nm@ti.com