Document Microchip LAN969x USART compatible.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
---
Changes in v3:
* Pick Acked-by from Conor

 Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
index 087a8926f8b4..375cd50bc5cc 100644
--- a/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
+++ b/Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml
@@ -24,6 +24,7 @@ properties:
           - const: atmel,at91sam9260-usart
       - items:
           - enum:
+              - microchip,lan9691-usart
               - microchip,sam9x60-usart
               - microchip,sam9x7-usart
               - microchip,sama7d65-usart
-- 
2.52.0