tpm: Add TPM 2.0 support to the Nuvoton i2c driver (NPCT6xx family)

The command flow is exactly the same, the core simply needs to be
told to enable TPM2 mode when the compatible string indicates a
TPM2.

Signed-off-by: Andrew Azmansky <andrew.zamansky@nuvoton.com>
Tested-by: Andrew Zamansky <andrew.zamansky@nuvoton.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>