toolchain: gcc: 5.4.0: fix patch formatting

git-am is quite picky when it comes to commit messages, this one needed
fixing.

Signed-off-by: Phil Sutter <phil@nwl.cc>

toolchain/gcc/patches/5.4.0/microblaze-enable-dwarf-eh-support.patch

@@ -1,5 +1,3 @@
-Fetched from Xilinx gcc git at https://github.com/Xilinx/gcc
-
 From 23c35173490ac2d6348a668dfc9c1a6eb62171f2 Mon Sep 17 00:00:00 2001
 From: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
 Date: Mon, 18 Jun 2012 20:18:13 +0200
@@ -25,6 +23,8 @@ Changelog
 
 Signed-off-by: David Holsgrove <david.holsgrove@xilinx.com>
 Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
+---
+Fetched from Xilinx gcc git at https://github.com/Xilinx/gcc
 ---
  gcc/common/config/microblaze/microblaze-common.c |  3 ---
  gcc/config/microblaze/microblaze-protos.h        |  1 +