boot.initrd.luks: add input_leds module

To get working caps lock lights already at stage 1, the input_leds
module needs to be loaded.

Closes #12456.

nixos/modules/system/boot/luksroot.nix

@@ -434,7 +434,9 @@ in
       ["firewire_ohci" "firewire_core" "firewire_sbp2"];
 
     # Some modules that may be needed for mounting anything ciphered
-    boot.initrd.availableKernelModules = [ "dm_mod" "dm_crypt" "cryptd" ] ++ luks.cryptoModules;
+    # Also load input_leds to get caps lock light working (#12456)
+    boot.initrd.availableKernelModules = [ "dm_mod" "dm_crypt" "cryptd" "input_leds" ]
+      ++ luks.cryptoModules;
 
     # copy the cryptsetup binary and it's dependencies
     boot.initrd.extraUtilsCommands = ''