hooklib: Allow proper passthrough of serial calls to real hardware (#26)

Only enabled / tested on IIDX CB and SDVX5

The point of this, is to allow rs232 hooks for only the descriptors that we hook.
This is because the emulation here is incomplete.
Although the IOCTL's do end up being passed to the real hardware, the game rejects some of the responses and hangs.
By short circuiting out, and calling the real Comm functions instead, it works.
And hence, card-reader passthrough works on IIDX25+/SDVX5+ finally without eamio-real

src/main/iidxhook-util/acio.c

@@ -14,6 +14,7 @@
 #include "acioemu/icca.h"
 
 #include "hook/iohook.h"
+#include "hooklib/rs232.h"
 
 #include "iidxhook-util/acio.h"
 
@@ -41,6 +42,8 @@ void iidxhook_util_acio_init(bool legacy_mode)
         ac_io_emu_icca_init(&iidxhook_util_acio_emu_icca[i],
             &iidxhook_util_acio_emu, i);
     }
+
+    rs232_hook_add_fd(iidxhook_util_acio_emu.fd);
 }
 
 void iidxhook_util_acio_fini(void)