Remove calls to psa_allocate_key

In PSA 1.0 keys are allocated implicitly by other functions
(like psa_import_key) and psa_allocate_key is not needed and does not
exist anymore.
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 3675443..4a466ea 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -3249,12 +3249,6 @@
          * Generate EC private key for ECDHE exchange.
          */
 
-        /* Allocate a new key slot for the private key. */
-
-        status = psa_allocate_key( &handshake->ecdh_psa_privkey );
-        if( status != PSA_SUCCESS )
-            return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
-
         /* The master secret is obtained from the shared ECDH secret by
          * applying the TLS 1.2 PRF with a specific salt and label. While
          * the PSA Crypto API encourages combining key agreement schemes
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index bf40275..d602477 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -635,9 +635,6 @@
     psa_key_derivation_operation_t generator =
         PSA_KEY_DERIVATION_OPERATION_INIT;
 
-    if( ( status = psa_allocate_key( &master_slot ) ) != PSA_SUCCESS )
-        return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
-
     if( md_type == MBEDTLS_MD_SHA384 )
         alg = PSA_ALG_TLS12_PRF(PSA_ALG_SHA_384);
     else