run_device_tests: Use 'fw_wp_state' to control write protect state
run_device_tests: Use 'fw_wp_state' to control write protect state

In hdctools/servo/data/servo_micro.xml 'fw_wp_en' control is described
as "Enables forwarding of write-protect gpio. Must assert this
and set fw_wp_vref prior to changing fw_wp.". It means that it needs
to be enabled, but write protect state is controlled by 'fw_wp'.

There is also 'fw_wp_state' control which is convenient wrapper for
this. It sets 'fw_wp_en', 'fw_wp_vref' and 'fw_wp'.

BUG=b:170432597
BRANCH=none
TEST=Connect icetower using microservo.
     sudo servod --board icetower
     ./test/run_device_tests.py --board dartmonkey
         --test flash_write_protect
     Make sure that test is passed and HOST MCU WP diode glows
     during test. Don't use 'dut-control' to set write protect state.

Signed-off-by: Patryk Duda <6aed17a362577cf10cb5675888c1635d522769c1@semihalf.com>
Cq-Depend: chromium:2928423
Change-Id: Ia6164e877549956e8efb7fb5cd47d8c0d5ce2872
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2929119
Reviewed-by: Craig Hesling <383db090fd8ef907a606ac8a9eccd2962bc489cf@chromium.org>

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