tpm: cr50_i2c: Make use of 'z' for printing size_t

tpm: cr50_i2c: Make use of 'z' for printing size_t

When printing the contents of an size_t variable we need to use z prefix
to the format character in order to get the correct format type
depending on 32 or 64bit-ness.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>