Spi protocol standardized by the TCG is now supported by most of TPM
vendors.

It supports SPI Bit Protocol as describe in the TCG PTP
specification (chapter 6.4.6 SPI Bit Protocol).

Irq mode is not supported.

This commit is based on the initial work by Peter Huewe.
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>