targets/fcdev3b.h: bring back CONFIG_TARGET_FCDEV3B C preprocessor symbol CONFIG_TARGET_FCMODEM is no longer used anywhere in our code base, thus it is being fully retired. OTOH, CONFIG_TARGET_FCDEV3B is being brought back: with our earlier FC modem family idea now being withdrawn in light of the discovery of Tango modules, FCDEV3B goes back to being its own unique target.

/* This file is needed just to make sure the archiver isn't called
 * with an empty list of object files. */

static void aci_dummy_dont_call_this(void)
{
}