drivers/hwmon/coretemp.c: remove unneeded #ifdef CONFIG_HOTPLUG_CPU

drivers/hwmon/coretemp.c: remove unneeded #ifdef CONFIG_HOTPLUG_CPU

register_hotcpu_notifier() is designed to make these ifdefs unnecessary.

Cc: Chen Gong <gong.chen@linux.intel.com>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Huaxu Wan <huaxu.wan@intel.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>