ARM: dts: microchip: sama7d65: add fifo-size to usart

When missing, add the atmel,fifo-size = <32> property for usart nodes in
flexcom.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20260102170135.70717-5-nicolas.ferre@microchip.com
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>

Author: noglitch

arch/arm/boot/dts/microchip/sama7d65.dtsi

@@ -414,6 +414,7 @@
 				dma-names = "tx", "rx";
 				atmel,use-dma-rx;
 				atmel,use-dma-tx;
+				atmel,fifo-size = <32>;
 				atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 				status = "disabled";
 			};
@@ -492,6 +493,7 @@
 				dma-names = "tx", "rx";
 				atmel,use-dma-rx;
 				atmel,use-dma-tx;
+				atmel,fifo-size = <32>;
 				atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 				status = "disabled";
 			};
@@ -517,6 +519,7 @@
 				dma-names = "tx", "rx";
 				atmel,use-dma-rx;
 				atmel,use-dma-tx;
+				atmel,fifo-size = <32>;
 				atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
 				status = "disabled";
 			};