tpm: drop 'iobase' from struct tpm_vendor_specific

Dropped the field 'iobase' from struct tpm_vendor_specific and migrated
it to the private structures of tpm_atmel and tpm_tis.

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>