ctrtool: Add support for inline decryption

ctrtool/aes_keygen.h

@@ -0,0 +1,8 @@
+#pragma once
+#include <stdint.h>
+
+/*
+	AES Key generator for the Nintendo 3DS (CTR) Consoles
+*/
+
+void ctr_aes_keygen(const uint8_t *x, const uint8_t *y, uint8_t *key);