Blackfin: disable syscontrol code for now
Looks like the initcode updates fell out of order during my merges. The
patch that really fixes up this code is part of power-on overhaul and so
is too large for merging at this point. Instead, we can disable the code
as no currently in-tree board depends on it. The next merge window will
fix things up properly.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>