Sshd, added port as option

Primarily so that it can be used in other modules since I default to a
non-standard port for obsecurity reasons.

nixosModules/services/ssh/service.nix

@@ -1,14 +1,18 @@
-{ config, pkgs, lib, ... }:
+{ config, lib, ... }:
 
 {
   options.sshd = {
     enable = lib.mkEnableOption "Enables ssh daemon";
+    port = lib.mkOption {
+      default = 922;
+      type = lib.types.port;
+    };
   };
 
   config = lib.mkIf config.sshd.enable {
     services.openssh = {
       enable = true;
-      ports = [ 922 ];
+      ports = [ config.sshd.port ];
       settings = {
         PasswordAuthentication = false;
         PermitRootLogin = "no";