RSE: Add attack tracking counter

Add non-volatile counter which is used for tracking hardware events
which could be indicative of a side-channel attack being performed
against the device. Once this counter hits max value, prevent the RSE
from booting in order to prevent further probing.

Change-Id: Ia9281fd23ce3c20db67c7c185c8edaddd8efc96a
Signed-off-by: Raef Coles <raef.coles@arm.com>