linuxkpi: Add pm_runtime.h

Provide dummy functions needed for drm-kmod.

Obtain from:	OpenBSD (via drm-kmod)
MFC after:      1 week
Sponsored by:	Beckhoff Automation GmbH & Co. KG
Differential Revision:	https://reviews.freebsd.org/D35568

sys/compat/linuxkpi/common/include/linux/pm_runtime.h

@@ -0,0 +1,43 @@
+/* Public domain. */
+
+#ifndef _LINUXKPI_LINUX_PM_RUNTIME_H_
+#define _LINUXKPI_LINUX_PM_RUNTIME_H_
+
+#include <linux/device.h>
+#include <linux/pm.h>
+
+#define pm_runtime_mark_last_busy(x) (void)(x)
+#define pm_runtime_use_autosuspend(x) (void)(x)
+#define pm_runtime_dont_use_autosuspend(x) (void)(x)
+#define pm_runtime_put_autosuspend(x) (void)(x)
+#define pm_runtime_set_autosuspend_delay(x, y) (void)(x); (void)(y)
+#define pm_runtime_set_active(x) (void)(x)
+#define pm_runtime_allow(x) (void)(x)
+#define pm_runtime_put_noidle(x) (void)(x)
+#define pm_runtime_forbid(x) (void)(x)
+#define pm_runtime_get_noresume(x) (void)(x)
+#define pm_runtime_put(x) (void)(x)
+#define pm_runtime_enable(x) (void)(x)
+#define pm_runtime_disable(x) (void)(x)
+#define pm_runtime_autosuspend(x) (void)(x)
+#define pm_runtime_resume(x) (void)(x)
+
+static inline int
+pm_runtime_get_sync(struct device *dev)
+{
+	return 0;
+}
+
+static inline int
+pm_runtime_get_if_in_use(struct device *dev)
+{
+	return 1;
+}
+
+static inline int
+pm_runtime_get_if_active(struct device *dev, bool x)
+{
+	return 1;
+}
+
+#endif	/* _LINUXKPI_LINUX_PM_RUNTIME_H_ */