DFP: Fix flash memory region creation bugs.
DFP: Fix flash memory region creation bugs.

- There were some bad bugs in computing of addresses of flash regions
  for different sector-size ranges, especially if the region started at
  a non-zero address.

pyocd/pyOCD,pyocd/pyOCD,mbedmicro/pyOCD,flit/pyOCD,flit/pyOCD,mbedmicro/pyOCD,mesheven/pyOCD,mbedmicro/pyOCD,mesheven/pyOCD,mesheven/pyOCD