tpm: drop list from struct tpm_vendor_specific

Dropped list from struct tpm_vendor_specific as it is not used in any
place.

It is initialized in tpm_i2c_infineon but not used at all in the code.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>