tpm: rename tpm_chip_find_get() to tpm_find_get_ops()

Rename tpm_chip_find_get() to tpm_find_get_ops() to more closely match
the tpm_put_ops() counter part.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>