lib: kobject_uevent is no longer dependant on CONFIG_HOTPLUG

CONFIG_HOTPLUG is being removed so kobject_uevent needs to always be
part of the library.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>