cpu: don't redeclare doinit on ppc64le

Follow-up fix for CL 206859. Also order the +build line alphabetically.

Change-Id: I568c8b3ee03161d4341c151e4ec7150cade51077
Reviewed-on: https://go-review.googlesource.com/c/sys/+/206864
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/cpu/cpu_linux_noinit.go b/cpu/cpu_linux_noinit.go
index 192198e..f65134f 100644
--- a/cpu/cpu_linux_noinit.go
+++ b/cpu/cpu_linux_noinit.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,!arm,!arm64,!s390x,!ppc64
+// +build linux,!arm,!arm64,!ppc64,!ppc64le,!s390x
 
 package cpu