tests: drivers: i2c: i2c_target_api: Cleanup after nRF54LM20 rename

Remove duplicated test configuration after
nrf54l20pdk/nrf54l20/cpuxxx was renamed to
nrf54lm20dk/nrf54lm20a/cpuxxx.

Signed-off-by: Sebastian Głąb <[email protected]>

Author: nordic-segl

tests/drivers/i2c/i2c_target_api/boards/nrf54l20pdk_nrf54l20_cpuapp.conf

@@ -1,3 +1,9 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 /*
  * SDA = P1.13 and P1.14
  * SCL = P1.23 and P1.24

tests/drivers/i2c/i2c_target_api/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -65,8 +65,8 @@ tests:
       - nrf5340dk/nrf5340/cpuapp
       - nrf54h20dk/nrf54h20/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
       - ophelia4ev/nrf54l15/cpuapp
     integration_platforms:
       - max32690evkit/max32690/m4
+      - nrf54l15dk/nrf54l15/cpuapp