[nrf fromtree] tests: drivers: spi: spi_controller_peripheral: Disable on nRF54L20pdk

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

Signed-off-by: Sebastian Głąb <[email protected]>
(cherry picked from commit 49734bf)

Author: nordic-segl

tests/drivers/spi/spi_controller_peripheral/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -62,6 +62,7 @@
 	overrun-character = <0x00>;
 	cs-gpios = <&gpio1 3 GPIO_ACTIVE_LOW>;
 	zephyr,pm-device-runtime-auto;
+
 	dut_spi_dt: test-spi-dev@0 {
 		compatible = "vnd,spi-device";
 		reg = <0>;

tests/drivers/spi/spi_controller_peripheral/boards/nrf54lm20dk_nrf54lm20a_cpuapp.overlay

@@ -8,12 +8,11 @@ common:
     fixture: gpio_spi_loopback
   platform_allow:
     - nrf52840dk/nrf52840
-    - nrf54l15dk/nrf54l15/cpuapp
-    - nrf54l20pdk/nrf54l20/cpuapp
-    - nrf54lm20dk/nrf54lm20a/cpuapp
     - nrf54h20dk/nrf54h20/cpuapp
     - nrf54h20dk/nrf54h20/cpurad
     - nrf54h20dk/nrf54h20/cpuppr
+    - nrf54l15dk/nrf54l15/cpuapp
+    - nrf54lm20dk/nrf54lm20a/cpuapp
     - ophelia4ev/nrf54l15/cpuapp
 
 tests:
@@ -79,10 +78,9 @@ tests:
     extra_args: DTC_OVERLAY_FILE="boards/nrf54h20dk_nrf54h20_cpuapp_fast.overlay"
     platform_exclude:
       - nrf52840dk/nrf52840
-      - nrf54l15dk/nrf54l15/cpuapp
       - nrf54h20dk/nrf54h20/cpurad
       - nrf54h20dk/nrf54h20/cpuppr
-      - nrf54l20pdk/nrf54l20/cpuapp
+      - nrf54l15dk/nrf54l15/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
       - ophelia4ev/nrf54l15/cpuapp
 
@@ -93,10 +91,9 @@ tests:
     extra_args: DTC_OVERLAY_FILE="boards/nrf54h20dk_nrf54h20_cpuapp_fast_spis.overlay"
     platform_exclude:
       - nrf52840dk/nrf52840
-      - nrf54l15dk/nrf54l15/cpuapp
       - nrf54h20dk/nrf54h20/cpurad
       - nrf54h20dk/nrf54h20/cpuppr
-      - nrf54l20pdk/nrf54l20/cpuapp
+      - nrf54l15dk/nrf54l15/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
       - ophelia4ev/nrf54l15/cpuapp