sim: bfin: push SIC mappings to device tree

sim: bfin: push SIC mappings to device tree

The machs.c file is the best place for holding cpu-specific details, so
restructure the way the SIC manages its ports to do just that.  Now the
SIC's have a standard set of input pins and the different line routing
from peripherals is kept in the device tree only.  This better models
the hardware where the SIC doesn't care about the exact peripheral that
is sending it stuff, just which input pin it gets it on.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>