fix(nix): update vendorHash and vendor dir for new deps

vendor/golang.org/x/sys/cpu/cpu_ppc64x.go

@@ -0,0 +1,16 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ppc64 || ppc64le
+
+package cpu
+
+const cacheLineSize = 128
+
+func initOptions() {
+	options = []option{
+		{Name: "darn", Feature: &PPC64.HasDARN},
+		{Name: "scv", Feature: &PPC64.HasSCV},
+	}
+}