pciehp: wait for 1000ms before LED operation after power off

After turning power off, we must wait for at least 1 second *before*
LED operation.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>