Adjust psa entropy inject tests to take as minimum seed size

the maximum of MBEDTLS_ENTROPY_MIN_PLATFORM and MBEDTLS_ENTROPY_BLOCK_SIZE
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index fe73d1d..cc5532a 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -4227,10 +4227,46 @@
 }
 
 #if ( defined(MBEDTLS_ENTROPY_NV_SEED) && defined(MBEDTLS_PSA_HAS_ITS_IO) )
+
+/* Support function for error conversion between psa_its error codes to psa crypto */
+static psa_status_t its_to_psa_error( psa_its_status_t ret )
+{
+    switch( ret )
+    {
+        case PSA_ITS_SUCCESS:
+            return( PSA_SUCCESS );
+
+        case PSA_ITS_ERROR_KEY_NOT_FOUND:
+            return( PSA_ERROR_EMPTY_SLOT );
+
+        case PSA_ITS_ERROR_STORAGE_FAILURE:
+            return( PSA_ERROR_STORAGE_FAILURE );
+
+        case PSA_ITS_ERROR_INSUFFICIENT_SPACE:
+            return( PSA_ERROR_INSUFFICIENT_STORAGE );
+
+        case PSA_ITS_ERROR_INVALID_KEY:
+        case PSA_PS_ERROR_OFFSET_INVALID:
+        case PSA_ITS_ERROR_INCORRECT_SIZE:
+        case PSA_ITS_ERROR_BAD_POINTER:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+        case PSA_ITS_ERROR_FLAGS_NOT_SUPPORTED:
+            return( PSA_ERROR_NOT_SUPPORTED );
+
+        case PSA_ITS_ERROR_WRITE_ONCE:
+            return( PSA_ERROR_OCCUPIED_SLOT );
+
+        default:
+            return( PSA_ERROR_UNKNOWN_ERROR );
+    }
+}
+
 psa_status_t mbedtls_psa_inject_entropy( const unsigned char *seed,
                                          size_t seed_size )
 {
     psa_status_t status;
+    psa_its_status_t its_status;
     struct psa_its_info_t p_info;
     if( global_data.initialized )
         return( PSA_ERROR_NOT_PERMITTED );
@@ -4240,16 +4276,20 @@
           ( seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE ) )
             return( PSA_ERROR_INVALID_ARGUMENT );
 
-    status = psa_its_get_info( MBEDTLS_RANDOM_SEED_ITS_UID, &p_info );
-    if( PSA_ITS_ERROR_KEY_NOT_FOUND == status ) /* No seed exists */
+    its_status = psa_its_get_info( MBEDTLS_RANDOM_SEED_ITS_UID, &p_info );
+    status = its_to_psa_error( its_status );
+
+    if( PSA_ITS_ERROR_KEY_NOT_FOUND == its_status ) /* No seed exists */
     {
-        status = psa_its_set( MBEDTLS_RANDOM_SEED_ITS_UID, seed_size, seed, 0 );
+        its_status = psa_its_set( MBEDTLS_RANDOM_SEED_ITS_UID, seed_size, seed, 0 );
+        status = its_to_psa_error( its_status );
     }
-    else if( PSA_ITS_SUCCESS == status )
+    else if( PSA_ITS_SUCCESS == its_status )
     {
         /* You should not be here. Seed needs to be injected only once */
         status = PSA_ERROR_NOT_PERMITTED;
     }
+    
     return( status );
 }
 #endif