leds: Add suspend/resume state flags to leds-gpio

Add an option to preserve LED state when suspending/resuming to the LED
gpio driver. Based on a suggestion from Robert Jarzmik.

Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/include/linux/leds.h b/include/linux/leds.h
index 17d277e..376fe07 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -141,7 +141,8 @@
 	const char *name;
 	const char *default_trigger;
 	unsigned 	gpio;
-	u8 		active_low;
+	u8 		active_low : 1;
+	u8		retain_state_suspended : 1;
 };
 
 struct gpio_led_platform_data {