vboot: workbuf alignment should always use 8

Rather than depending on the architecture and environment to
provide the correct memory alignment (__BIGGEST_ALIGNMENT__),
hardcode to 8, which should be sufficient for all cases.

(Previously, by using __BIGGEST_ALIGNMENT__, this is set to
16 in all known cases, which is unnecessarily large.)

Update vb2_workbuf tests to be more flexible according to
VB2_WORKBUF_ALIGN value.

BUG=b:124141368
TEST=make clean && make runtests
TEST=Try values of VB2_WORKBUF_ALIGN=2,4,8,16,32,64
BRANCH=none

Change-Id: I819586119fa3102fa423a01e0737e6864c05d752
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/1911921
Reviewed-by: Joel Kitching <kitching@chromium.org>
Commit-Queue: Joel Kitching <kitching@chromium.org>
Tested-by: Joel Kitching <kitching@chromium.org>
2 files changed