pata_acpi: fix build breakage if !CONFIG_PM

There are configurations where CONFIG_ACPI but !CONFIG_PM.  In this
case, pata_acpi can be selected but won't build.  Fix it.

Reported by Avuton Olrich.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Avuton Olrich <avuton@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/ata/pata_acpi.c

@@ -370,8 +370,10 @@ static struct pci_driver pacpi_pci_driver = {
 	.id_table		= pacpi_pci_tbl,
 	.probe			= pacpi_init_one,
 	.remove			= ata_pci_remove_one,
+#ifdef CONFIG_PM
 	.suspend		= ata_pci_device_suspend,
 	.resume			= ata_pci_device_resume,
+#endif
 };
 
 static int __init pacpi_init(void)