vboot2: add a flag to indicate firmware was selected by vboot2

TEST=Done manually on Nyan:
  localhost ~ # sudo /tmp/crossystem fw_vboot2
  0
  localhost ~ # sudo /tmp/crossystem fw_vboot2=1
  localhost ~ # sudo /tmp/crossystem fw_vboot2
  0
  # reboot with vboot2 firmware
  localhost ~ # /tmp/crossystem fw_vboot2
  1

BUG=none
BRANCH=none
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>

Change-Id: I6ed553c48bdfebf07393f6f5f46832a60971314a
Reviewed-on: https://chromium-review.googlesource.com/205664
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
diff --git a/utility/crossystem.c b/utility/crossystem.c
index 5ffb5af..6b16ff4 100644
--- a/utility/crossystem.c
+++ b/utility/crossystem.c
@@ -53,6 +53,7 @@
   {"ecfw_act", IS_STRING, "Active EC firmware"},
   {"fmap_base", 0, "Main firmware flashmap physical address", "0x%08x"},
   {"fwb_tries", CAN_WRITE, "Try firmware B count (writable)"},
+  {"fw_vboot2", 0, "1 if firmware was selected by vboot2 or 0 otherwise"},
   {"fwid", IS_STRING, "Active firmware ID"},
   {"fwupdate_tries", CAN_WRITE,
    "Times to try OS firmware update (writable, inside kern_nv)"},