leds: lp55xx: Convert to use GPIO descriptors

The LP55xx driver is already using the of_gpio() functions to
pick a global GPIO number for "enable" from the device tree and
request the line. Simplify it by just using a GPIO descriptor.

Make sure to keep the enable GPIO line optional, change the
naming from "lp5523_enable" to "LP55xx enable" to reflect that
this is used on all LP55xx LED drivers.

Cc: Milo Kim <milo.kim@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

include/linux/platform_data/leds-lp55xx.h

@@ -12,6 +12,8 @@
 #ifndef _LEDS_LP55XX_H
 #define _LEDS_LP55XX_H
 
+#include <linux/gpio/consumer.h>
+
 /* Clock configuration */
 #define LP55XX_CLOCK_AUTO	0
 #define LP55XX_CLOCK_INT	1
@@ -49,7 +51,7 @@ enum lp8501_pwr_sel {
  * @clock_mode        : Input clock mode. LP55XX_CLOCK_AUTO or _INT or _EXT
  * @setup_resources   : Platform specific function before enabling the chip
  * @release_resources : Platform specific function after  disabling the chip
- * @enable            : EN pin control by platform side
+ * @enable_gpiod      : enable GPIO descriptor
  * @patterns          : Predefined pattern data for RGB channels
  * @num_patterns      : Number of patterns
  * @update_config     : Value of CONFIG register
@@ -65,7 +67,7 @@ struct lp55xx_platform_data {
 	u8 clock_mode;
 
 	/* optional enable GPIO */
-	int enable_gpio;
+	struct gpio_desc *enable_gpiod;
 
 	/* Predefined pattern data */
 	struct lp55xx_predef_pattern *patterns;