Move MBEDTLS_BLOCK_CIPHER_NO_DECRYPT to correct section

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/configs/config-tfm.h b/configs/config-tfm.h
index a21d041..1925cdc 100644
--- a/configs/config-tfm.h
+++ b/configs/config-tfm.h
@@ -45,9 +45,9 @@
 #undef MBEDTLS_PLATFORM_STD_EXIT_SUCCESS
 #undef MBEDTLS_PLATFORM_STD_EXIT_FAILURE
 
-// We expect TF-M to pick this up soon
-#define MBEDTLS_BLOCK_CIPHER_NO_DECRYPT
-
 /***********************************************************************
  * Local changes to crypto config below this delimiter
  **********************************************************************/
+
+// We expect TF-M to pick this up soon
+#define MBEDTLS_BLOCK_CIPHER_NO_DECRYPT