[QEMU] Add a TIS device model compliant to the 1.2 TPM specification.

[QEMU] Add a TIS device model compliant to the 1.2 TPM specification.
It implements all registers necessary to make the Linux TIS driver
work (tpm_tis.c). All of the basic registers supported by this type of
device are implemented. Also the locality selection has been
implemented, but has not been tested. The legacy registers as
described in the specification are not supported.

Current caveat: The device has so far not yet been integrated with the
virtual TPM available in the repository. It will require changes to
the virtual TPM spawned by the vTPM manager to offer an additional message
interface. The TIS interface itself then needs to have an additional
transport implemented. (see vTPMTransmit array).

The relevant specification for the device model can be found here:
https://www.trustedcomputinggroup.org/groups/pc_client/TCG_PCClientTPMSpecification_1-20_1-00_FINAL.pdf

Signed-off-by: Stefan Berger <stefanb@us.ibm.com>