drivers: lpuart: Dont say we support async without DMA

The dma has to be enabled on the platform in order for ASYNC API to
work. This can be indicated by whether or not any LPUART node has the
`dmas` property set.

Signed-off-by: Declan Snyder <[email protected]>

Author: decsny

drivers/serial/Kconfig.mcux_lpuart

@@ -1,6 +1,4 @@
-# MCUXpresso SDK LPUART
-
-# Copyright (c) 2017, NXP
+# Copyright 2017, 2025 NXP
 # SPDX-License-Identifier: Apache-2.0
 
 config UART_MCUX_LPUART
@@ -10,7 +8,7 @@ config UART_MCUX_LPUART
 	depends on CLOCK_CONTROL
 	select SERIAL_HAS_DRIVER
 	select SERIAL_SUPPORT_INTERRUPT
-	select SERIAL_SUPPORT_ASYNC
+	select SERIAL_SUPPORT_ASYNC if $(dt_compat_any_has_prop,$(DT_COMPAT_NXP_LPUART),dmas)
 	select DMA if UART_ASYNC_API
 	select PINCTRL
 	help