ACPI / x86: Make PWM2 device always present at Lenovo Yoga Book

Lenovo Yoga Book uses PWM2 for controlling keyboard backlight but this
device is hidden in the DSDT in Windows version of notebook (if OSID == 1).

Make this device always present for this notebook.
Signed-off-by: NYauhen Kharuzhy <jekhor@gmail.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/x86/utils.c

@@ -56,6 +56,11 @@ static const struct always_present_id always_present_ids[] = {
 	 */
 	ENTRY("80860F09", "1", ICPU(INTEL_FAM6_ATOM_SILVERMONT), {}),
 	ENTRY("80862288", "1", ICPU(INTEL_FAM6_ATOM_AIRMONT), {}),
+
+	/* Lenovo Yoga Book uses PWM2 for keyboard backlight control */
+	ENTRY("80862289", "2", ICPU(INTEL_FAM6_ATOM_AIRMONT), {
+			DMI_MATCH(DMI_PRODUCT_NAME, "Lenovo YB1-X9"),
+		}),
 	/*
 	 * The INT0002 device is necessary to clear wakeup interrupt sources
 	 * on Cherry Trail devices, without it we get nobody cared IRQ msgs.