tpm: Rework the assertion of physical presence

tpm: Rework the assertion of physical presence

Rework the assertion of physical presence by calling assert_physical_presence
in tpm_setup. This call will assert physical presence if SW assertion is
possible or by checking whether HW physical presence is enabled.
The TPM menu will only be shown if physical presence is asserted or HW
physical presence is enabled after this call.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>