cgpt: Update behavior of GptUpdateKernelWithEntry

In order to support slots, we need to update behavior of
GptUpdateKernelWithEntry so that:
1. Invalid - Marks kernel entry as invalid
2. Active - Marks kernel entry as active

CQ-DEPEND=CL:336906
BUG=chrome-os-partner:51807
BRANCH=None
TEST=Compiles successfully "sudo emerge vboot_reference" "emerge-smaug
vboot_reference". "make -j runtests" successful.

Change-Id: If248b3c6bdd23d03cb1dd24f4e21cacef5cc3f26
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/335942
Commit-Ready: Furquan Shaikh <furquan@chromium.org>
Tested-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed