sensors-detect: Document the --stat option in the man page

prog/detect/sensors-detect.8

@@ -38,6 +38,8 @@ Run in automatic, non-interactive mode. Assume default answers to all
 questions. Note that this isn't necessarily safe as the internal logic may
 lead to potentially dangerous probes being attempted. See the WARNING section
 below.
+.IP "--stat"
+Display I2C address statistics.
 
 .SH WARNING
 sensors-detect needs to access the hardware for most of the chip detections.