nouveau: fix acpi_lid_open undefined

When CONFIG_ACPI_BUTTON=m (and probably when ACPI_BUTTON is not enabled)
and NOUVEAU is built-in (not as a loadable module):

nouveau_connector.c:(.text+0xe17ce): undefined reference to `acpi_lid_open'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/nouveau/nouveau_connector.c

@@ -241,7 +241,8 @@ nouveau_connector_detect(struct drm_connector *connector)
 	if (nv_encoder && nv_connector->native_mode) {
 		unsigned status = connector_status_connected;
 
-#ifdef CONFIG_ACPI
+#if defined(CONFIG_ACPI_BUTTON) || \
+	(defined(CONFIG_ACPI_BUTTON_MODULE) && defined(MODULE))
 		if (!nouveau_ignorelid && !acpi_lid_open())
 			status = connector_status_unknown;
 #endif