crypto/internal/fips/nistec: remove P-256 from generate.go

It's not been autogenerated since CL 627937.

Change-Id: I2d2e249c2bab673342ee42a48582b082c6958cdd
Reviewed-on: https://go-review.googlesource.com/c/go/+/629836
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

src/crypto/internal/fips/nistec/generate.go

@@ -26,22 +26,15 @@ import (
 )
 
 var curves = []struct {
-	P         string
-	Element   string
-	Params    *elliptic.CurveParams
-	BuildTags string
+	P       string
+	Element string
+	Params  *elliptic.CurveParams
 }{
 	{
 		P:       "P224",
 		Element: "fiat.P224Element",
 		Params:  elliptic.P224().Params(),
 	},
-	{
-		P:         "P256",
-		Element:   "fiat.P256Element",
-		Params:    elliptic.P256().Params(),
-		BuildTags: "(!amd64 && !arm64 && !ppc64le && !s390x) || purego",
-	},
 	{
 		P:       "P384",
 		Element: "fiat.P384Element",
@@ -86,7 +79,6 @@ func main() {
 		if err := t.Execute(buf, map[string]interface{}{
 			"P": c.P, "p": p, "B": B, "Gx": Gx, "Gy": Gy,
 			"Element": c.Element, "ElementLen": elementLen,
-			"BuildTags": c.BuildTags,
 		}); err != nil {
 			log.Fatal(err)
 		}
@@ -145,10 +137,6 @@ const tmplNISTEC = `// Copyright 2022 The Go Authors. All rights reserved.
 
 // Code generated by generate.go. DO NOT EDIT.
 
-{{ if .BuildTags }}
-//go:build {{ .BuildTags }}
-{{ end }}
-
 package nistec
 
 import (