tpm: add AUTH1 cmds for LoadKey2 and GetPubKey

Extend the tpm library with support for single authorized (AUTH1) commands
as specified in the TCG Main Specification 1.2. (The internally used helper
functions are implemented in a way that they could also be used for double
authorized commands if someone needs it.)

Provide enums with the return codes from the TCG Main specification.

For now only a single OIAP session is supported.

OIAP authorized version of the commands TPM_LoadKey2 and TPM_GetPubKey are
provided. Both features are available using the 'tpm' command, too.

Authorized commands are enabled with CONFIG_TPM_AUTH_SESSIONS. (Note that
this also requires CONFIG_SHA1 to be enabled.)

Signed-off-by: Reinhard Pfau <reinhard.pfau@gdsys.cc>
Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>
Acked-by: Che-Liang Chiou <clchiou@chromium.org>
Signed-off-by: Andy Fleming <afleming@freescale.com>