tests: subsys: usb: negotiated_speed: Switch to nrf54lm20dk

Switch test from nrf54lm20pdk to nrf54lm20dk.

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

Author: nordic-segl

tests/subsys/usb/negotiated_speed/testcase.yaml

@@ -12,8 +12,7 @@ tests:
       - nrf54h20dk/nrf54h20/cpuapp
     platform_allow:
       - nrf54h20dk/nrf54h20/cpuapp
-      - nrf54lm20pdk/nrf54lm20a/cpuapp
-      - [email protected]/nrf54lm20a/cpuapp
+      - nrf54lm20dk/nrf54lm20a/cpuapp
     extra_configs:
       - CONFIG_LOG_DEFAULT_LEVEL=3
       - CONFIG_APP_MSC_STORAGE_RAM=y