linux: Add 5.3, linux-libre: 16791 -> 16794

Update linuxPackages_latest to 5.3

pkgs/os-specific/linux/kernel/linux-5.3.nix

@@ -0,0 +1,18 @@
+{ stdenv, buildPackages, fetchurl, perl, buildLinux, modDirVersionArg ? null, ... } @ args:
+
+with stdenv.lib;
+
+buildLinux (args // rec {
+  version = "5.3";
+
+  # modDirVersion needs to be x.y.z, will automatically add .0 if needed
+  modDirVersion = if (modDirVersionArg == null) then concatStrings (intersperse "." (take 3 (splitString "." "${version}.0"))) else modDirVersionArg;
+
+  # branchVersion needs to be x.y
+  extraMeta.branch = concatStrings (intersperse "." (take 2 (splitString "." version)));
+
+  src = fetchurl {
+    url = "mirror://kernel/linux/kernel/v5.x/linux-${version}.tar.xz";
+    sha256 = "1ck70ns130nqf6xy02bwm67y00yh46lhjzdajq7zzx1wa6bw7wvq";
+  };
+} // (args.argsOverride or {}))

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

@@ -4,7 +4,7 @@
 
     # Update this if linux_latest-libre fails to build.
     # $ curl https://www.fsfla.org/svn/fsfla/software/linux-libre/releases/branches/ | grep -Eo 'Revision [0-9]+'
-    rev = "16791";
+    rev = "16794";
     sha256 = "1lpaka4hs7yrpnrzfybd6radjylwvw2p4aly68pypykqs2srvm7j";
   }
 , ...