tpm_crb is a device for TPM 2.0 Command Response Buffer (CRB)
Interface as defined in TCG PC Client Platform TPM Profile (PTP)
Specification Family “2.0” Level 00 Revision 01.03 v22.

The PTP allows device implementation to switch between TIS and CRB
model at run time, but given that CRB is a simpler device to
implement, I chose to implement it as a different device.

The device doesn't implement other locality than 0 for now (my laptop
TPM doesn't either, so I assume this isn't so bad)

Tested with some success with Linux upstream and Windows 10, seabios &
modified ovmf. The device is recognized and correctly transmit
command/response with passthrough & emu. However, we are missing PPI
ACPI part atm.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>