backlight: Allow properties to be passed at registration

Values such as max_brightness should be set before backlights are
registered, but the current API doesn't allow that. Add a parameter to
backlight_device_register and update drivers to ensure that they
set this correctly.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index ef61497..46435ac 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -559,10 +559,14 @@
 	release_buffer();
 
 	if (max_intensity) {
-		dell_backlight_device = backlight_device_register(
-			"dell_backlight",
-			&platform_device->dev, NULL,
-			&dell_ops);
+		struct backlight_properties props;
+		memset(&props, 0, sizeof(struct backlight_properties));
+		props.max_brightness = max_intensity;
+		dell_backlight_device = backlight_device_register("dell_backlight",
+								  &platform_device->dev,
+								  NULL,
+								  &dell_ops,
+								  &props);
 
 		if (IS_ERR(dell_backlight_device)) {
 			ret = PTR_ERR(dell_backlight_device);
@@ -570,7 +574,6 @@
 			goto fail_backlight;
 		}
 
-		dell_backlight_device->props.max_brightness = max_intensity;
 		dell_backlight_device->props.brightness =
 			dell_get_intensity(dell_backlight_device);
 		backlight_update_status(dell_backlight_device);