tpm: add PCR authentication commands support

Add support for the TPM2_PCR_SetAuthPolicy and
TPM2_PCR_SetAuthValue commands.

Change the command file and the help accordingly.

Note: These commands could not be tested because the TPMs available
do not support them, however they could be useful for someone else.
The user is warned by the command help.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>