tpm2: add marshaling/unmarshaling layer

TPM commands need to be serialized (marshaled) to be sent to the
device, and the responses need to be de-serialized (unmarshaled) to be
properly interpreted by upper layers.

This layer does not exist in TPM1.2 coreboot implementation, all TPM
commands used there were hardcoded as binary arrays. Availability of
the marshaling/unmarshaling layer makes it much easier to add new TPM
commands to the code.

Command and response structures used in these functions are defined in
Parts 2 and 3 of the TCG issued document

   Trusted Platform Module Library
   Family "2.0"
   Level 00 Revision 01.16
   October 30, 2014

BRANCH=none
BUG=chrome-os-partner:50645
TEST=with the rest of the patches applied it is possible to
     successfully initialize firmware and kernel TPM spaces.

Change-Id: I80b3f971e347bb30ea08f820ec3dd27e1656c060
Signed-off-by: Martin Roth <martinroth@chromium.org>
Original-Commit-Id: 0782d9d452efb732e85d1503fccfcb4bf9f69a68
Original-Change-Id: I202276ef9a43c28b5f304f901ac5b91048878b76
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/353915
Original-Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Original-Reviewed-by: Darren Krahn <dkrahn@chromium.org>
Reviewed-on: https://review.coreboot.org/15570
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@googlemail.com>

src/lib/Makefile.inc

@@ -55,6 +55,7 @@ ifeq ($(MOCK_TPM),1)
 libverstage-y += mocked_tlcl.c
 else
 libverstage-$(CONFIG_TPM) += tlcl.c
+libverstage-$(CONFIG_TPM2) += tpm2_marshaling.c
 libverstage-$(CONFIG_TPM2) += tpm2_tlcl.c
 endif