kernel: Move to Linux v4.13.4-openpower1

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/linux/0002-Release-OpenPower-kernel.patch b/openpower/linux/0002-Release-OpenPower-kernel.patch
index 071161b..da99bae 100644
--- a/openpower/linux/0002-Release-OpenPower-kernel.patch
+++ b/openpower/linux/0002-Release-OpenPower-kernel.patch
@@ -1,6 +1,6 @@
 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
 From: Joel Stanley <joel@jms.id.au>
-Date: Tue, 5 Sep 2017 17:14:24 +1000
+Date: Thu, 28 Sep 2017 11:52:54 +0930
 Subject: [PATCH 2/2] Release OpenPower kernel
 
 Signed-off-by: Joel Stanley <joel@jms.id.au>
@@ -9,13 +9,13 @@
  1 file changed, 1 insertion(+), 1 deletion(-)
 
 diff --git a/Makefile b/Makefile
-index 8aad6bc50d52..2ab5bcdfe63a 100644
+index 159901979dec..b6ca367a928c 100644
 --- a/Makefile
 +++ b/Makefile
 @@ -1,7 +1,7 @@
  VERSION = 4
  PATCHLEVEL = 13
- SUBLEVEL = 2
+ SUBLEVEL = 4
 -EXTRAVERSION =
 +EXTRAVERSION = -openpower1
  NAME = Fearless Coyote