[TPM] Add 3 more test cases to the xm testsuite that extend the

[TPM] Add 3 more test cases to the xm testsuite that extend the
state of a PCR register and test that the value remains the same during
a suspend/resume cycle and during live and non-live local migration.
The patch adapts existing tests to the changes in the driver (moving of
the sysfs entry). Some problems with existing tests are fixed.

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