ao-tools/ao-flash-lpc: Adapt to current openocd LPC support

Openocd 0.9.0 has generalized the lpc11xx support for all lpc11xx
processors, not just the lpc11u14. This replaces the specific
lpc11u14.cfg with the general lpc11xx.cfg file.

Unlike the build we were using, this doesn't adjust the
'verify' command to adapt for the checksum which gets added during the
flashing process. Hence, we disable verification and trust that if the
flash loader works to load the OS, it's fine.

Signed-off-by: Keith Packard <keithp@keithp.com>