arm64: dts: fvp: Add information about L1 and L2 caches

Add the information about L1 and L2 caches on FVP RevC platform.
Though the cache size is configurable through the model parameters,
having default values in the device tree helps to exercise and debug
any code utilising the cache information without the need of real
hardware.

Link: https://lore.kernel.org/r/20221118151017.704716-1-sudeep.holla@arm.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>