build: fix issue with multiple peripherals on one block

previous shield implementation assigned multiple
peripherals into single hardware block
which is not valid configuration

removed the unused interfaces from arduino adapter.
if there is need for them in the future they can be added as needed.

Signed-off-by: Robert Gałat <[email protected]>

Author: RobertGalatNordic

boards/shields/simple_arduino_adapter/boards/nrf54l15dk_common.overlay

@@ -7,6 +7,9 @@
  * Arduino header adapter shield for nrf54l15dk
  * This shield maps nrf54l15dk pins to Arduino header format
  * allowing standard Arduino shields to work on nrf54l15dk
+ * 
+ * IMPORTANT: This implementation avoids serial interface conflicts by using
+ * separate hardware blocks for I2C, SPI, and UART functions.
  */
 
 / {
@@ -40,28 +43,24 @@
     };
 };
 
+/*
+ * Serial Interface Assignment Strategy (avoiding conflicts):
+ * 
+ * Address Mapping:
+ * - 0xc6000 (Serial Interface 20): UART20 (console) - RESERVED
+ * - 0xc8000 (Serial Interface 22): I2C22 (Arduino I2C)
+ * - 0x104000 (Serial Interface 30): SPI30 (Arduino SPI)
+ * 
+ * This assignment ensures no conflicts between console and Arduino functions.
+ */
+
 arduino_spi: &spi30 {
     status = "okay";
     pinctrl-0 = <&spi30_default_alt>;
     pinctrl-1 = <&spi30_sleep_alt>;
     pinctrl-names = "default", "sleep";
 };
 
-arduino_i2c: &i2c20 {
-    status = "okay";
-    pinctrl-0 = <&i2c20_default_alt>;
-    pinctrl-1 = <&i2c20_sleep_alt>;
-    pinctrl-names = "default", "sleep";
-};
-
-arduino_serial: &uart21 {
-    status = "okay";
-    current-speed = <115200>;
-    pinctrl-0 = <&uart21_default_alt>;
-    pinctrl-1 = <&uart21_sleep_alt>;
-    pinctrl-names = "default", "sleep";
-};
-
 &pinctrl {
     spi30_default_alt: spi30_default_alt {
         group1 {
@@ -79,44 +78,4 @@ arduino_serial: &uart21 {
             low-power-enable;
         };
     };
-    i2c20_default_alt: i2c20_default_alt {
-        group1 {
-            psels = <NRF_PSEL(TWIM_SDA, 0, 4)>,
-                    <NRF_PSEL(TWIM_SCL, 0, 5)>;
-        };
-    };
-
-    i2c20_sleep_alt: i2c20_sleep_alt {
-        group1 {
-            psels = <NRF_PSEL(TWIM_SDA, 0, 4)>,
-                    <NRF_PSEL(TWIM_SCL, 0, 5)>;
-            low-power-enable;
-        };
-    };
-
-    uart21_default_alt: uart21_default_alt {
-        group1 {
-            psels = <NRF_PSEL(UART_TX, 0, 6)>,
-                    <NRF_PSEL(UART_RX, 0, 7)>;
-        };
-    };
-
-    uart21_sleep_alt: uart21_sleep_alt {
-        group1 {
-            psels = <NRF_PSEL(UART_TX, 0, 6)>,
-                    <NRF_PSEL(UART_RX, 0, 7)>;
-            low-power-enable;
-        };
-    };
-};
-
-/ {
-    aliases {
-        smtc-hal-uart = &uart20;
-        smtc-watchdog = &wdt31;
-    };
-};
-
-&wdt31 {
-    status = "okay";
 };