Provide types for `void` pointers in internal functions

[steven-bellock]

For example

void libspdm_reset_message_encap_e(libspdm_context_t *spdm_context, void *session_info)
{
    libspdm_session_info_t *spdm_session_info;

would become

void libspdm_reset_message_encap_e(libspdm_context_t *spdm_context, libspdm_session_info_t *session_info)
{