tpm: reduce tpm polling delay in tpm_tis_core

The existing wait_for_tpm_stat() polls for the chip status after
5msec sleep. As per TCG ddwg input, it is expected that tpm might
return status in few usec. So, reducing the delay in polling to
1msec.
Similarly, get_burstcount() function sleeps for 5msec before
retrying for next query to burstcount in a loop. If it takes
lesser time for TPM to return, this 5msec delay is longer than
necessary.

After this change, performance on a TPM 1.2 with an 8 byte
burstcount for 1000 extends improved from ~14sec to ~9sec.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>