media: pci/pt1: suppress compiler warning in xtensa arch

Found and reported by kbuild test robot:
Message ID: <201805052003.MC007f9h%fengguang.wu@intel.com>
and holding an address of an empty struct in .driver.pm does no harm
when CONFIG_PM_SLEEP is not defined.
Signed-off-by: Akihiro Tsukada <tskd08@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/pci/pt1/pt1.c

@@ -1443,9 +1443,7 @@ static struct pci_driver pt1_driver = {
 	.probe		= pt1_probe,
 	.remove		= pt1_remove,
 	.id_table	= pt1_id_table,
-#ifdef CONFIG_PM_SLEEP
 	.driver.pm	= &pt1_pm_ops,
-#endif
 };
 
 module_pci_driver(pt1_driver);