tpm: move endianness conversion of ordinals to tpm_input_header

Move CPU native value to big-endian conversion of ordinals to the
tpm_input_header declarations.

With the previous and this patch it will now be possible to modify TPM 1.2
functions to use tpm_buf_init(), which expects CPU native value for the
tag and ordinal arguments.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.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>