Revert "samples: bluetooth: Fix event_trigger sample on 54h"

This reverts commit 7d2aca3.

The workaround is no longer needed as the root cause of the problem
(incorrect runtime device PM in the UARTE driver) was fixed.

Signed-off-by: Andrzej Głąbek <[email protected]>

Author: anangl

samples/bluetooth/event_trigger/boards/nrf54h20dk_nrf54h20_cpurad.conf

@@ -9,5 +9,3 @@ CONFIG_PSA_CRYPTO_DRIVER_OBERON=n
 CONFIG_PSA_SSF_CRYPTO_CLIENT=y
 CONFIG_MBEDTLS_PSA_CRYPTO_C=y
 CONFIG_NRF_SECURITY=y
-
-CONFIG_PM=n