leds: el15203000: Correct headers (of*.h -> mod_devicetable.h)

There is no user of of*.h headers, but mod_devicetable.h.
Update header block accordingly.
Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Oleh Kravchenko <oleg@kaa.org.ua>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

drivers/leds/leds-el15203000.c

@@ -4,8 +4,9 @@
 
 #include <linux/delay.h>
 #include <linux/leds.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
-#include <linux/of_device.h>
+#include <linux/property.h>
 #include <linux/spi/spi.h>
 
 /*