ectool and burn_my_ec need to use the same lower-level interface to
the EC flash commands, rather than duplicating calling the low-level
flash read/write/erase commands.
This is a precursor to refactoring the low-level commands to support
SPI/STM32L in a follow-up CL.
BUG=chrome-os-partner:20571
BRANCH=none
TEST=in a root shell, burn_my_ec flashes both RO and RW EC code
Change-Id: I4c72690100d86dbff03b7dacc2fb248b571d3820
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/60266
