Use the previously introduced endian conversion routines in the driver
and the TPM2 library.
Use packed TPM message header structure to make it easy to access
unaligned header fields.
BRANCH=none
BUG=chrome-os-partner:43025
TEST=the tpm startup command still succeeds.
Change-Id: I03078481664858a19617e248f98cb20013c27445
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/312585