ARM: at91: Documentation: add lan966 family

Add the new LAN966 ARMv7 based SoC family from Microchip.

Signed-off-by: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
[nicolas.ferre@microchip.com: move entry as part of new Cortex-A7 core type]
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20211004105926.5696-3-kavyasree.kotagiri@microchip.com

Documentation/arm/microchip.rst

@@ -149,6 +149,14 @@ the Microchip website: http://www.microchip.com.
 
           Coming soon
 
+      - lan966 family
+        - lan9662
+        - lan9668
+
+          * Datasheet
+
+          Coming soon
+
     * ARM Cortex-M7 MCUs
       - sams70 family