crosvm: use underscores for hex constants.
crosvm: use underscores for hex constants.

BUG=None
TEST=None

Change-Id: I1833862771baa922c58bc8be91c5bd0d898e9c35
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3329285
Reviewed-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Commit-Queue: Junichi Uekawa <6bd240a6ce32463e272bb69c685a8e946b33ac05@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm