update nixpkgs, remove seabios version override

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1602333914,
+        "lastModified": 1602666561,
-        "narHash": "sha256-ossU2LFWerfPK/HkCvAom6WvBrQ80vq9CTApMCPaHMs=",
+        "narHash": "sha256-TByS4XBC8VQ6hjr686MqLylYMTruNJsOS6FKOq53p3c=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "b70ac01b380722591c89d40ea31e0ac2463d87ec",
+        "rev": "ffde8a8e1ed76caa1d213c3209dee7f75b57a20d",
         "type": "github"
       },
       "original": {

pkgs/coreboot-payload-seabios/default.nix

@@ -8,12 +8,6 @@
 seabios.overrideAttrs (oA: rec {
   pname = "coreboot-payload-seabios";
 
-  version = "1.14.0";
-  src = fetchurl {
-    url = "https://www.seabios.org/downloads/seabios-${version}.tar.gz";
-    sha256 = "1zc1brgafbbf5hmdr1qc1p859cabpz73l8sklq83xa4sn9icqw7b";
-  };
-
   configurePhase = ''
     runHook preConfigure
     cp ${coreboot.writeConfig seabiosConfig} .config