hwmon: (coretemp) Relax target temperature range check

The current temperature range check of MSR_IA32_TEMPERATURE_TARGET
seems too strict to me, some TjMax values documented in
Documentation/hwmon/coretemp wouldn't pass. Relax the check so that
all the documented values pass.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Carsten Emde <C.Emde@osadl.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>