arm64: Juno: Fix the GIC node address label and the frequency of FAXI clock.

During the review of the Juno DT files I've noticed that the GIC
node label had two digits swapped leading to a different address
being shown in the /sys/devices fs.

Sudeep also pointed that public revisions of the Juno documentation
list a different frequency for the FAXI system than what the one
I've been using when creating the DT file. Verified with the firmware
people to be the correct value in the shipped systems.

Reported-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Jon Medhurst <tixy@linaro.org>