tpm: Use durations returned from TPM

The TPM driver currently discards the durations values returned
from the TPM. The check of the response packet needs to consider that
the return_code field is 0 on success and the size of the expected
packet is equivalent to the header size + u32 length indicator for the
TPM_GetCapability() result + 3 timeout indicators of type u32.

v4:
- sysfs entry 'durations' is now a patch of its own
- the work-around for TPMs reporting durations in milliseconds is now in a
  patch of its own

v3:
- sysfs entry now called 'durations' to resemble TPM-speak (previously
  was called 'timeouts')

v2:
- adjusting all timeouts for TPM devices reporting timeouts in msec rather
  than usec
- also displaying in sysfs whether the timeouts are 'original' or 'adjusted'

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>