factory_install: Check main/EC write protection consistency only after clearing TPM

For devices that needs clearing TPM and using factory install shim for that,
they may only disabled BIOS write protection and keep EC protected.

BUG=chrome-os-partner:5851
TEST=(1) get an Alex with bios WP=off, ec WP=on
     (2) boot with factory install shim
     (3) Seeing TPM cleared message

Change-Id: I887d6ff56e917349843053c999cace4b9abb525b
Reviewed-on: http://gerrit.chromium.org/gerrit/8187
Reviewed-by: Tammo Spalink <tammo@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
1 file changed