arm64: dts: NS2: reserve memory for Nitro firmware

Nitro firmware is loaded into memory by the bootloader at a specific
location.  Set this memory range aside to prevent the kernel from using
it.
Signed-off-by: NJon Mason <jon.mason@broadcom.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>

arch/arm64/boot/dts/broadcom/ns2.dtsi

@@ -30,6 +30,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/memreserve/ 0x81000000 0x00200000;
+
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/clock/bcm-ns2.h>