backlight: move lp855x header into platform_data directory

The lp855x header is used only in the platform side, so it can be moved
into platform_data directory

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/lp855x_bl.c

@@ -14,7 +14,7 @@
 #include <linux/i2c.h>
 #include <linux/backlight.h>
 #include <linux/err.h>
-#include <linux/lp855x.h>
+#include <linux/platform_data/lp855x.h>
 
 /* Registers */
 #define BRIGHTNESS_CTRL		0x00