tpm: tis_i2c: Fix sanity check interrupt enable mask

The sanity check mask for TPM_INT_ENABLE register was off by 8 bits,
resulting in failure to probe if the TPM_INT_ENABLE register was a
valid value.

Fixes: bbc23a07

 ("tpm: Add tpm_tis_i2c backend for tpm_tis_core")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>