Moved PPI attributes to the character device directory. This aligns with
the sysfs guidelines and makes them race free because they are created
atomically with the character device as part of device_register().The
character device and the sysfs attributes appear at the same time to the
user space.

As part of this change we enable PPI attributes also for TPM 2.0
devices. In order to retain backwards compatibility with TPM 1.x
devices, a symlink is created to the platform device directory.
Signed-off-by: NJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: NJason Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Tested-by: Mimi Zohar <zohar@linux.vnet.ibm.com> (on TPM 1.2)
Tested-by: NChris J Arges <chris.j.arges@canonical.com>
Tested-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NPeter Huewe <peterhuewe@gmx.de>