kernel generic: Don't use stdenv.cross

pkgs/os-specific/linux/kernel/generic.nix

···
   kernelPatches ? []
 , ignoreConfigErrors ? stdenv.platform.name != "pc"
 , extraMeta ? {}
+, hostPlatform
 , ...
 }:
 
···
     arch = stdenv.platform.kernelArch;
 
     crossAttrs = let
-        cp = stdenv.cross.platform;
+        cp = hostPlatform.platform;
       in {
         arch = cp.kernelArch;
         platformName = cp.name;
···
     };
 
   config = configWithPlatform stdenv.platform;
-  configCross = configWithPlatform stdenv.cross.platform;
+  configCross = configWithPlatform hostPlatform.platform;
 
   nativeDrv = lib.addPassthru kernel.nativeDrv passthru;
 

pkgs/os-specific/linux/kernel/linux-3.10.nix

···
-{ stdenv, fetchurl, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchurl, perl, buildLinux, ... } @ args:
 
 import ./generic.nix (args // rec {
   version = "3.10.105";

pkgs/os-specific/linux/kernel/linux-4.11.nix

···
-{ stdenv, fetchurl, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchurl, perl, buildLinux, ... } @ args:
 
 import ./generic.nix (args // rec {
   version = "4.11.7";

pkgs/os-specific/linux/kernel/linux-4.4.nix

···
-{ stdenv, fetchurl, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchurl, perl, buildLinux, ... } @ args:
 
 import ./generic.nix (args // rec {
   version = "4.4.73";

pkgs/os-specific/linux/kernel/linux-4.9.nix

···
-{ stdenv, fetchurl, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchurl, perl, buildLinux, ... } @ args:
 
 import ./generic.nix (args // rec {
   version = "4.9.34";

pkgs/os-specific/linux/kernel/linux-chromiumos-3.18.nix

···
-{ stdenv, fetchgit, perl, buildLinux, ncurses, ... } @ args:
+{ stdenv, hostPlatform, fetchgit, perl, buildLinux, ncurses, ... } @ args:
 
 # ChromiumOS requires a 64bit build host
 assert stdenv.is64bit;

pkgs/os-specific/linux/kernel/linux-hardened-copperhead.nix

···
-{ stdenv, fetchFromGitHub, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchFromGitHub, perl, buildLinux, ... } @ args:
 
 let
   version = "4.11.7";

pkgs/os-specific/linux/kernel/linux-mptcp.nix

···
-{ stdenv, fetchurl, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchurl, perl, buildLinux, ... } @ args:
 
 import ./generic.nix (args // rec {
   mptcpVersion = "0.91.3";

pkgs/os-specific/linux/kernel/linux-rpi.nix

···
-{ stdenv, fetchFromGitHub, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchFromGitHub, perl, buildLinux, ... } @ args:
 
 let
   modDirVersion = "4.9.24";

pkgs/os-specific/linux/kernel/linux-testing.nix

···
-{ stdenv, fetchurl, perl, buildLinux, ... } @ args:
+{ stdenv, hostPlatform, fetchurl, perl, buildLinux, ... } @ args:
 
 import ./generic.nix (args // rec {
   version = "4.12-rc6";