tpm: Use the ops structure instead of a copy in tpm_vendor_specific

This builds on the last commit to use the ops structure in the core
and reduce the size of tpm_vendor_specific.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>