8641HPCN: Config file cleanup

There are several items in the config file that were hardcoded
but that should really be based on other config options, since
the regions are contiguous and depend on being so.  This cleans
that up a bit.  Also, add BR_PHYS_ADDR() macro to convert
addresses into the proper format for BR registers.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>