[nrf fromtree] tests: drivers: uart: add 54l15 fast uart

Add the fast uart instance of 54l15 for testing

Signed-off-by: Piotr Krzyzanowski <[email protected]>
(cherry picked from commit 6d8eb18)

Author: nordic-pikr

tests/drivers/uart/uart_async_api/boards/nrf54l15dk_nrf54l15_cpuapp.overlay

@@ -1,5 +1,9 @@
 /* SPDX-License-Identifier: Apache-2.0 */
 
+&spi00 {
+	status = "disabled";
+};
+
 &pinctrl {
 	uart21_default_alt: uart21_default_alt {
 		group1 {
@@ -15,6 +19,21 @@
 			low-power-enable;
 		};
 	};
+
+	uart00_default_alt: uart00_default_alt {
+		group1 {
+			psels = <NRF_PSEL(UART_TX, 2, 8)>,
+				<NRF_PSEL(UART_RX, 2, 7)>;
+		};
+	};
+
+	uart00_sleep_alt: uart00_sleep_alt {
+		group1 {
+			psels = <NRF_PSEL(UART_TX, 2, 8)>,
+				<NRF_PSEL(UART_RX, 2, 7)>;
+			low-power-enable;
+		};
+	};
 };
 
 dut: &uart21 {
@@ -24,3 +43,11 @@ dut: &uart21 {
 	pinctrl-names = "default", "sleep";
 	current-speed = <115200>;
 };
+
+dut2: &uart00 {
+	status = "okay";
+	pinctrl-0 = <&uart00_default_alt>;
+	pinctrl-1 = <&uart00_sleep_alt>;
+	pinctrl-names = "default", "sleep";
+	current-speed = <4000000>;
+};