tpm: fix PPI traversal

There's a bug in PPI traversal. It traverses through the whole device
tree and considers anything that has PPI interface as the correct
PPI interface. Instead ACPI handle should be passed and PPI should
be only looked up under that ACPI device. This is racy on devices
that have two TPM ACPI devices.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>