[nrf toup][nrfconnect] Enable storing DAC key in KMU by default

Enabled storing the DAC private key in KMU if it is available.
It enables storing the DAC private key in KMU for nRF54L15 device.

Signed-off-by: Arkadiusz Balys <arkadiusz.balys@nordicsemi.no>
(cherry picked from commit aa968a6)
Signed-off-by: Adrian Gielniewski <adrian.gielniewski@nordicsemi.no>

Author: ArekBalysNordic

config/nrfconnect/chip-module/Kconfig

@@ -366,6 +366,7 @@ if CHIP_CRYPTO_PSA_MIGRATE_DAC_PRIV_KEY
 
 choice CHIP_CRYPTO_PSA_DAC_PRIV_KEY_MIGRATION_DEST
 	prompt "Destination for DAC private key migration"
+	default CHIP_CRYPTO_PSA_DAC_PRIV_KEY_KMU if CRACEN_LIB_KMU
 	default CHIP_CRYPTO_PSA_DAC_PRIV_KEY_ITS
 
 config CHIP_CRYPTO_PSA_DAC_PRIV_KEY_ITS