test: drivers: i2s_speed: add nucleo u575

Add Nucleo U575ZI Q overlay and conf in i2s speed test

Signed-off-by: Mario Paja <mariopaja@hotmail.com>

Author: mariopaja

tests/drivers/i2s/i2s_speed/boards/nucleo_u575zi_q.conf

@@ -0,0 +1,16 @@
+#
+# Copyright (c) 2026 Mario Paja
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+CONFIG_HEAP_MEM_POOL_SIZE=128
+CONFIG_I2S_TEST_SEPARATE_DEVICES=y
+CONFIG_I2S_TEST_USE_GPIO_LOOPBACK=y
+CONFIG_I2S_TEST_USE_I2S_DIR_BOTH=n
+
+# 88200Hz is not supported by Hardware
+CONFIG_I2S_TEST_SKIP_SAMPLERATE_88200=y
+
+# Clock is optimized for 44100Hz, 96000Hz is not supported
+CONFIG_I2S_TEST_SKIP_SAMPLERATE_96000=y

tests/drivers/i2s/i2s_speed/boards/nucleo_u575zi_q.overlay

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+/*
+ * Copyright (c) 2026 Mario Paja
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	aliases {
+		i2s-node0 = &sai1_b;
+		i2s-node1 = &sai1_a;
+	};
+};
+
+&pll2 {
+	/* 44.1KHz (-0.03% Error) */
+	div-m = <1>;
+	mul-n = <79>;
+	div-q = <2>;
+	div-r = <2>;
+	div-p = <7>;
+	clocks = <&clk_msis>;
+	status = "okay";
+};
+
+&sai1_a {
+	pinctrl-0 = <&sai1_sck_a_pe5 &sai1_fs_a_pe4 &sai1_sd_a_pe6>;
+	pinctrl-names = "default";
+	status = "okay";
+	mclk-divider = "div-256";
+	fifo-threshold = "empty";
+	dma-names = "tx";
+};
+
+&sai1_b {
+	pinctrl-0 = <&sai1_sck_b_pf8 &sai1_fs_b_pf9 &sai1_sd_b_pe3>;
+	pinctrl-names = "default";
+	status = "okay";
+	mclk-divider = "div-256";
+	fifo-threshold = "empty";
+	dma-names = "rx";
+};