linux: Partially revert "linux: drop hacky passing around of positions" (#457651)

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

@@ -51,6 +51,8 @@ lib.makeOverridable (
     version,
     # The kernel pname (should be set for variants)
     pname ? "linux",
+    # Position of the Linux build expression
+    pos ? null,
     # Additional kernel make flags
     extraMakeFlags ? [ ],
     # The name of the kernel module directory
@@ -551,6 +553,8 @@ lib.makeOverridable (
 
     karch = stdenv.hostPlatform.linuxArch;
 
+    pos = lib.optionalDrvAttr (pos != null) pos;
+
     meta = {
       # https://github.com/NixOS/nixpkgs/pull/345534#issuecomment-2391238381
       broken = withRust && lib.versionOlder version "6.12";

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

@@ -293,6 +293,7 @@ let
           configfile
           modDirVersion
           ;
+        pos = builtins.unsafeGetAttrPos "version" args;
 
         config = {
           CONFIG_MODULES = "y";