take maximum processor Mhz (#16740)

* take maximum processor Mhz

* remove break

* cl: add cl for 16740

---------

Co-authored-by: Seth Hoenig <shoenig@duck.com>

.changelog/16740.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+client/fingerprint: detect fastest cpu core during cpu performance fallback
+```

helper/stats/cpu.go

@@ -63,8 +63,9 @@ func Init() error {
 
 			for _, infoStat := range cpuInfoStats {
 				cpuModelName = infoStat.ModelName
-				cpuPowerCoreMHz = uint64(infoStat.Mhz)
-				break
+				if uint64(infoStat.Mhz) > cpuPowerCoreMHz {
+					cpuPowerCoreMHz = uint64(infoStat.Mhz)
+				}
 			}
 
 			// compute ticks using only power core, until we add support for