flash_ec: add support for SWD, nrf51, and hadoken

BUG=none
TEST=manual
BRANCH=none

flash_ec --board=hadoken
flash_ec --board=npcx_evb
flash_ec --board=samus

Use openocd in SWD mode to flash the nRF51 chip.

Use warm_reset to exit DEBUG mode.

Change-Id: Iaf2827d4ce5be6d61431a3de7ab4f86aa4adde02
Signed-off-by: Myles Watson <mylesgw@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/287039
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
6 files changed