tpm: Add a basic API implementation for TPMv2

Add support for TPMv2 versions of API functions. So far this is not
complete as the standard is quite large, but it implements everything
currently available for TPMv2 in U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>