tpmd2: Add Support for the Intel TSS

* configure.ac: Check for Intel TSS.
* tpm2d/intel-tss.h: New.
* tpm2d/tpm2.h (HAVE_INTEL_TSS): Use the Intel code.

The Intel TSS is somewhat of a moving target, so this wraps support
for this TSS into tpm2daemon. Unfortunately this wrapper uses some
APIs that are only present in a relatively recent Intel TSS, so it
looks like it will only work with version 2.4.0 or higher.

• Add header blurb; see previous patch.
• Add new file to the Makefile

• Signed-off-by: Werner Koch <wk@gnupg.org>