samples: subsys: logging: logger: add stm32h750b-dk conf

Enable the sample to run on stm32h750b-dk board with async
UART backend

Signed-off-by: Abderrahmane JARMOUNI <git@jarmouni.me>

Author: JarmouniA

samples/subsys/logging/logger/boards/stm32h750b_dk.conf

@@ -0,0 +1,5 @@
+CONFIG_UART_ASYNC_API=y
+CONFIG_LOG_BACKEND_UART_ASYNC=y
+
+# for Log UART Backend DMA buffers
+CONFIG_NOCACHE_MEMORY=y

samples/subsys/logging/logger/boards/stm32h750b_dk.overlay

@@ -0,0 +1,23 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* console UART */
+&usart3 {
+	dmas = <&dmamux1 2 46 STM32_DMA_PERIPH_TX>,
+		<&dmamux1 3 45 STM32_DMA_PERIPH_RX>;
+	dma-names = "tx", "rx";
+	status = "okay";
+};
+
+&dma1 {
+	status = "okay";
+};
+
+&dma2 {
+	status = "okay";
+};
+
+&dmamux1 {
+	status = "okay";
+};