mfd: at91-usart: Make it selectable for ARCH_LAN969X

LAN969x uses the AT91 USART IP so make it selectable for ARCH_LAN969X.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20250131171739.1044701-2-robert.marko@sartura.hr
Signed-off-by: Lee Jones <lee@kernel.org>

Author: robimarko

drivers/mfd/Kconfig

@@ -138,7 +138,7 @@ config MFD_AAT2870_CORE
 config MFD_AT91_USART
 	tristate "AT91 USART Driver"
 	select MFD_CORE
-	depends on ARCH_AT91 || COMPILE_TEST
+	depends on ARCH_AT91 || ARCH_LAN969X || COMPILE_TEST
 	help
 	  Select this to get support for AT91 USART IP. This is a wrapper
 	  over at91-usart-serial driver and usart-spi-driver. Only one function