nixos/luksroot: Remove explicit cryptd from boot.initrd.availableKernelModules

crytpd is a helper module which *may* be compiled based on architecture
and/or crypto algorithms which are supported (built) in the kernel.
Since not all kernels need cryptd to do LUKS-based encryption, move
cryptd to cryptoModules which can be configured based on the built
kernel.

nixos/modules/system/boot/luksroot.nix

@@ -647,6 +647,7 @@ in
         "sha512"
         "af_alg"
         "algif_skcipher"
+        "cryptd"
       ];
       description = ''
         A list of cryptographic kernel modules needed to decrypt the root device(s).
@@ -1135,7 +1136,6 @@ in
     boot.initrd.availableKernelModules = [
       "dm_mod"
       "dm_crypt"
-      "cryptd"
       "input_leds"
     ]
     ++ luks.cryptoModules