include/linux/cpu.h: Update comments to reflect reality

Two minor changes to comments:

* Remove reference to drivers/base/sys.c, removed in 0a962657.
* CPUs are now exported by sysfs via devices/system/cpu.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
1 file changed