Quiet coretemp probe

Only the first device will print
coretemp0: <CPU On-Die Thermal Sensors> numa-domain 0 on cpu0
instead of all hyper threads

Submitted by:	kbowling
Reviewed by:	imp, sbruno
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D15727

sys/dev/coretemp/coretemp.c

@@ -145,6 +145,9 @@ coretemp_probe(device_t dev)
 
 	device_set_desc(dev, "CPU On-Die Thermal Sensors");
 
+	if (!bootverbose && device_get_unit(dev) != 0)
+		device_quiet(dev);
+
 	return (BUS_PROBE_GENERIC);
 }