flash_ec: Add workaround for dartmonkey + servo_micro
flash_ec: Add workaround for dartmonkey + servo_micro

An outstanding issue prevents flashing dartmonkey with a servo_micro.
The exact root cause is still unknown, but it's been observed that
repeating the FPMCU reset sequence twice makes the operation succeed.

BUG=b:177331210
TEST=util/flash_ec --board=dartmonkey --verbose
BRANCH=none

Signed-off-by: Andrea Grandi <f017805e76e0e7a74072a3bac1b6e29e65eedeab@google.com>
Change-Id: Ic4e69728b62245d814569db0944e3134452807f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3825659
Reviewed-by: Patryk Duda <213d388d1c6ea6afd34b87da9fc4415c3231b04c@google.com>
Reviewed-by: Tom Hughes <fc5c12f30a5ed2baa0581f44ee14ad1eb7b20d83@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec