This adds a new function to the internal target interface
to allow the target to get control before reset is complete
so that it can do any additional work. On this target there
is a proprietary internal bit that has to be reset in some
cases to allow the core to continue operating.
The new function returns a stop reason which must be translated in gdb server.
In the case of a watchpoint hit, the address is returned by a pointer parameter.
Simplify the extenal interface for set/clear breaki-/watchpoints.