kernel: move to Linux 4.12.5-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 16caf13..806396a 100644
--- a/openpower/linux/0002-Release-OpenPower-kernel.patch
+++ b/openpower/linux/0002-Release-OpenPower-kernel.patch
@@ -9,13 +9,13 @@
  1 file changed, 1 insertion(+), 1 deletion(-)
 
 diff --git a/Makefile b/Makefile
-index f5bbee480317..e05cc38a2137 100644
+index 382e967b0792..832de374937a 100644
 --- a/Makefile
 +++ b/Makefile
 @@ -1,7 +1,7 @@
  VERSION = 4
  PATCHLEVEL = 12
- SUBLEVEL = 3
+ SUBLEVEL = 5
 -EXTRAVERSION =
 +EXTRAVERSION = -openpower1
  NAME = Fearless Coyote