cmd: tpm: add a subcommand device

cmd: tpm: add a subcommand device

The command tpm (and tpm2) search the tpm and use it.
On sandbox, there are two tpm (tpm 1.x and tpm 2.0).
So the command tpm and tpm2 are always executed with
the first tpm (tpm 1.x), and the command tpm2 always
fails.

This add a subcommand device to command tpm and
command tpm2. Then the command tpm and tpm2 use
the device selected with the subcommand device.

To be compatible with previous behaviour, if the
subcommand device is not used before a tpm (or tpm2)
command, the device 0 is selected.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>