drm: bochs: fix warnings

Regular nightly randconfig build testing discovered these warnings:

drivers/gpu/drm/bochs/bochs_drv.c💯12: warning: 'bochs_pm_suspend' defined but not used [-Wunused-function]
drivers/gpu/drm/bochs/bochs_drv.c:117:12: warning: 'bochs_pm_resume' defined but not used [-Wunused-function]

Fix these by adding the same condition that SET_SYSTEM_SLEEP_PM_OPS()
uses.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/bochs/bochs_drv.c

@@ -97,6 +97,7 @@ static struct drm_driver bochs_driver = {
 /* ---------------------------------------------------------------------- */
 /* pm interface                                                           */
 
+#ifdef CONFIG_PM_SLEEP
 static int bochs_pm_suspend(struct device *dev)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
@@ -131,6 +132,7 @@ static int bochs_pm_resume(struct device *dev)
 	drm_kms_helper_poll_enable(drm_dev);
 	return 0;
 }
+#endif
 
 static const struct dev_pm_ops bochs_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(bochs_pm_suspend,