drivers/saul: add sensor type for particulate matter

drivers/include/saul.h

@@ -101,6 +101,7 @@ enum {
     SAUL_SENSE_RSSI     = 0x93,     /**< sensor: RSSI */
     SAUL_SENSE_CHARGE   = 0x94,     /**< sensor: coulomb counter */
     SAUL_SENSE_CURRENT  = 0x95,     /**< sensor: ammeter */
+    SAUL_SENSE_PM       = 0x96,     /**< sensor: particulate matter */
     SAUL_CLASS_ANY      = 0xff      /**< any device - wildcard */
     /* extend this list as needed... */
 };

drivers/saul/saul_str.c

@@ -57,8 +57,9 @@ const char *saul_class_to_str(const uint8_t class_id)
         case SAUL_SENSE_RSSI:      return "SENSE_RSSI";
         case SAUL_SENSE_CHARGE:    return "SENSE_CHARGE";
         case SAUL_SENSE_CURRENT:   return "SENSE_CURRENT";
-        case SAUL_CLASS_ANY:       return "CLASS_ANY";
         case SAUL_SENSE_OCCUP:     return "SENSE_OCCUP";
+        case SAUL_SENSE_PM:        return "SENSE_PM";
+        case SAUL_CLASS_ANY:       return "CLASS_ANY";
         default:                   return "CLASS_UNKNOWN";
     }
 }