dm: tpm: Add a uclass for Trusted Platform Modules

dm: tpm: Add a uclass for Trusted Platform Modules

Add a new uclass for TPMs which uses almost the same TIS (TPM Interface
Specification) as is currently implemented. Since init() is handled by the
normal driver model probe() method, we don't need to implement that. Also
rename the transfer method to xfer() which is a less clumbsy name.

Once all drivers and users are converted to driver model we can remove the
old code.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Christophe Ricard<christophe-h.ricard@st.com>
Reviewed-by: Heiko Schocher <hs@denx.de>