Move old_typec_match to the new structs

It was a hidden static variable of the policy engine, which would've
been a problem in a multi-port device.  Now it won't be anymore.

lib/include/pdb_pe.h

     bool _min_power;
     /* The number of hard resets we've sent */
     int8_t _hard_reset_counter;
+    /* The result of the last Type-C Current match comparison */
+    int8_t _old_tcc_match;
     /* Queue for the PE mailbox */
     msg_t _mailbox_queue[PDB_MSG_POOL_SIZE];
 };

lib/src/policy_engine.c

  */
 static enum policy_engine_state pe_sink_source_unresponsive(struct pdb_config *cfg)
 {
-    static int old_tcc_match = -1;
     int tcc_match = cfg->dpm.evaluate_typec_current(cfg, fusb_get_typec_current());
 
     /* If the last two readings are the same, set the output */
-    if (old_tcc_match == tcc_match) {
+    if (cfg->pe._old_tcc_match == tcc_match) {
         cfg->dpm.transition_typec(cfg);
     }
 
     /* Remember whether or not the last measurement succeeded */
-    old_tcc_match = tcc_match;
+    cfg->pe._old_tcc_match = tcc_match;
 
     /* Wait tPDDebounce between measurements */
     chThdSleep(PD_T_PD_DEBOUNCE);
 
     /* Initialize the mailbox */
     chMBObjectInit(&cfg->pe.mailbox, cfg->pe._mailbox_queue, PDB_MSG_POOL_SIZE);
+    /* Initialize the old_tcc_match */
+    cfg->pe._old_tcc_match = -1;
 
     while (true) {
         switch (state) {