tpm2tss-genkey - add support for tpm2-tools serialized handle files.

[rowanmoul]

When using tpm2tss-genkey the parent object in the TPM (such as a Primary Key) can only be specified with a hex handle (eg 0x81000003).
It would be good to add support for handle files produced by the -o option of tpm2_evictcontrol. The man page for that tool specifically mentions these being safer to use than a raw handles. Since it is a binary format I am not sure why without digging into the code but I assume these files also include the object's name to allow for verification that the handle actually points to the expected object (assuming no tampering with the serialized handle file)

[AndreasFuchsTPM]

Yes, nice idea. For anyone interested in implementing this, the file can be parsed using Esys_TR_Deserialize()

But be aware that this would also need an extension of the PEM format file.