* ocd.c: move ocd_write_bytes proto to ocd.h since it is used
by ppc-bdm.c, use OCD_LOG_FILE to help debugging, define
BDM_BREAKPOINT if not defined in tm.h
(ocd_error): add new error cases
(ocd_start_remote): send the OCD_INIT command before
OCD_AYT and OCD_GET_VERSION calls
(ocd_write_bytes): no longer static
(ocd_insert_breakpoint): no longer static
(ocd_remove_breakpoint): new
* ocd.h: add protos for ocd_write_bytes, ocd_insert_breakpoint,
and ocd_remove_breakpoint
* ppc-bdm.c: change bdm_ppc_ops so we call ocd_insert_breakpoint
and ocd_remove_breakpoint instead of memory_insert_breakpoint
and memory_remove_breakpoint.
(bdm_ppc_open): after calling ocd_open, modify DER
register so interrupts will drop us into debugging mode, finally
disable the watchdog timer on the board so we don't leave BDM
mode unexpectedly.