[nrf fromlist] tests: drivers: uart: uart_pm: Cleanup after nRF54LM20 rename

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

Upstream PR #: 92901

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

Author: nordic-segl

tests/drivers/uart/uart_pm/boards/nrf54l20pdk_nrf54l20_cpuapp.overlay

@@ -4,15 +4,14 @@ common:
     - uart
   harness: ztest
   platform_allow:
+    - nrf52_bsim
     - nrf52840dk/nrf52840
+    - nrf5340bsim/nrf5340/cpuapp
+    - nrf54h20dk/nrf54h20/cpuapp
     - nrf54l09pdk/nrf54l09/cpuapp
     - nrf54l15dk/nrf54l15/cpuapp
-    - nrf54l20pdk/nrf54l20/cpuapp
-    - nrf54lm20dk/nrf54lm20a/cpuapp
     - nrf54l15bsim/nrf54l15/cpuapp
-    - nrf54h20dk/nrf54h20/cpuapp
-    - nrf52_bsim
-    - nrf5340bsim/nrf5340/cpuapp
+    - nrf54lm20dk/nrf54lm20a/cpuapp
     - ophelia4ev/nrf54l15/cpuapp
   harness_config:
     fixture: gpio_loopback
@@ -33,14 +32,13 @@ tests:
       - CONFIG_UART_0_ENHANCED_POLL_OUT=n
     extra_args: DTC_OVERLAY_FILE="boards/nrf52840dk_nrf52840.overlay;nrf_rx_disable.overlay"
     platform_exclude:
+      - nrf52_bsim
+      - nrf5340bsim/nrf5340/cpuapp
+      - nrf54h20dk/nrf54h20/cpuapp
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
-      - nrf54lm20dk/nrf54lm20a/cpuapp
       - nrf54l15bsim/nrf54l15/cpuapp
-      - nrf54h20dk/nrf54h20/cpuapp
-      - nrf52_bsim
-      - nrf5340bsim/nrf5340/cpuapp
+      - nrf54lm20dk/nrf54lm20a/cpuapp
       - ophelia4ev/nrf54l15/cpuapp
 
   drivers.uart.pm.enhanced_poll:
@@ -49,11 +47,10 @@ tests:
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
     platform_exclude:
+      - nrf54h20dk/nrf54h20/cpuapp
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
-      - nrf54h20dk/nrf54h20/cpuapp
       - ophelia4ev/nrf54l15/cpuapp
 
   drivers.uart.pm.int_driven:
@@ -70,11 +67,10 @@ tests:
       - CONFIG_UART_ASYNC_API=n
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
     platform_exclude:
+      - nrf54h20dk/nrf54h20/cpuapp
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
-      - nrf54h20dk/nrf54h20/cpuapp
       - ophelia4ev/nrf54l15/cpuapp
 
   drivers.uart.pm.async:
@@ -91,9 +87,8 @@ tests:
       - CONFIG_UART_0_ASYNC=y
       - CONFIG_UART_0_ENHANCED_POLL_OUT=y
     platform_exclude:
+      - nrf54h20dk/nrf54h20/cpuapp
       - nrf54l09pdk/nrf54l09/cpuapp
       - nrf54l15dk/nrf54l15/cpuapp
-      - nrf54l20pdk/nrf54l20/cpuapp
       - nrf54lm20dk/nrf54lm20a/cpuapp
-      - nrf54h20dk/nrf54h20/cpuapp
       - ophelia4ev/nrf54l15/cpuapp