tests: drivers: uart: uart_async_api: add support for nucleo_h753zi

- add .conf and .overlay with appropriate configurations for
      nucleo_h753zi
- update testcase.yaml file for CI testing

Signed-off-by: Fabrice DJIATSA <[email protected]>

Author: djiatsaf-st

tests/drivers/uart/uart_async_api/boards/nucleo_h753zi.conf

@@ -0,0 +1 @@
+CONFIG_DCACHE=n

tests/drivers/uart/uart_async_api/boards/nucleo_h753zi.overlay

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2025 STMicroelectronics
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+dut: &usart2 {
+	dmas = <&dmamux1 2 44 STM32_DMA_PERIPH_TX>,
+	       <&dmamux1 3 43 STM32_DMA_PERIPH_RX>;
+	dma-names = "tx", "rx";
+	pinctrl-0 = <&usart2_tx_pd5 &usart2_rx_pd6>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
+&dmamux1 {
+	status = "okay";
+};

tests/drivers/uart/uart_async_api/testcase.yaml

@@ -35,7 +35,9 @@ tests:
     extra_configs:
       - CONFIG_UART_WIDE_DATA=y
     arch_allow: arm
-    platform_allow: nucleo_h743zi
+    platform_allow:
+      - nucleo_h743zi
+      - nucleo_h753zi
     integration_platforms:
       - nucleo_h753zi
   drivers.uart.async_api.nrf_uart: