ARM: dts: at91/trivial: Fix USART1 definition for at91sam9g45

Fix a typo. No functional change made by this patch.

Signed-off-by: Jay Foster <jayfoster@ieee.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

arch/arm/boot/dts/at91sam9g45.dtsi

@@ -570,7 +570,7 @@
 					};
 				};
 
-				uart1 {
+				usart1 {
 					pinctrl_usart1: usart1-0 {
 						atmel,pins =
 							<AT91_PIOB 4 AT91_PERIPH_A AT91_PINCTRL_NONE