Remove more remnants of the old "jtag_device" syntax.
Don't [format "%s.cpu" $_CHIPNAME] ... it's needless complexity.
Remove various non-supported "-variant" target options; they're not
needed often at all.
Flag some of the board files as needing to have and use target files
for the TAP and target declarations.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
