dracut: install TPM2 TCTIs with inst_libdir_file instead of removed-from-dracut-ng inst_library

We can't pull in 91tpm2-tss if installing TPM2 backend
instead of installing the TCTIs manually because it's
  require_binaries tpm2

Initrds produced are identical.

References: https://todo.sr.ht/~nabijaczleweli/tzpfms/3

initrd/dracut/module-setup.sh

@@ -25,8 +25,7 @@ _get_backend() {
 
 _install_tpm2() {
 	inst_binary zfs-tpm2-load-key
-	# shellcheck disable=SC2046
-	inst_library $(find /usr/lib -name 'libtss2-tcti*.so*')  # TODO: there's got to be a better way™!
+	inst_libdir_file 'libtss2-tcti*.so*'
 	command -v tpm2_dictionarylockout > /dev/null && inst_binary tpm2_dictionarylockout
 }