samples: keys: identity key usage

Enable ECDSA and the R1 256 bit curve for the
identity key sample since the samples imports
a key pair of that type.

This change is needed because of the new Oberon
PSA configuration system.

Signed-off-by: Georgios Vasilakis <georgios.vasilakis@nordicsemi.no>

samples/keys/identity_key_usage/prj.conf

@@ -14,6 +14,8 @@ CONFIG_MAIN_STACK_SIZE=8192
 CONFIG_NRF_SECURITY=y
 CONFIG_PSA_CRYPTO_DRIVER_CC3XX=y
 CONFIG_PSA_CRYPTO_DRIVER_OBERON=n
+CONFIG_PSA_WANT_ALG_ECDSA=y
+CONFIG_PSA_WANT_ECC_SECP_R1_256=y
 CONFIG_MBEDTLS_PSA_CRYPTO_C=y
 CONFIG_MBEDTLS_ENABLE_HEAP=y
 CONFIG_MBEDTLS_HEAP_SIZE=8192