tests: drivers: uart: uart_async_api: add nucleo_c092rc overlay

Add a overlay for the nucleo_c092 testing usart4 and dma
channels 6 and 7. These are all not available in smaller STM32C0 SoCs.

Signed-off-by: Thomas Stranger <[email protected]>

Author: str4t0m

tests/drivers/uart/uart_async_api/boards/nucleo_c092rc.overlay

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: Apache-2.0 */
+
+&usart4 {
+	/* available on ST morpho connector CN10 pins 4 and 22 */
+	pinctrl-0 = <&usart4_tx_pc1 &usart4_rx_pc0>;
+	pinctrl-names = "default";
+	current-speed = <115200>;
+	status = "okay";
+};
+
+
+dut: &usart4 {
+	dmas = <&dmamux1 5 57 STM32_DMA_PERIPH_TX>,
+	       <&dmamux1 6 56 STM32_DMA_PERIPH_RX>;
+	dma-names = "tx", "rx";
+};
+
+&dma1 {
+	status = "okay";
+};
+
+&dmamux1 {
+	status = "okay";
+};