tpm/st33zp24/spi: Use functions name with st33zp24_spi_ prefix

Make sure every function name use st33zp24_spi_ prefix.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>