video: add lm3533 backlight driver

This is basic lm3533 driver only with bank A and backlight cell
support.

Tested-by: Andreas Westman Dorcsak <hedmoo@yahoo.com> # LG P880 T30
Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # LG P895 T30
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 9b7abd4..2be73d5 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -606,6 +606,15 @@
 	help
 	   HLCDC supports video output to an attached LCD panel.
 
+config BACKLIGHT_LM3533
+	bool "Backlight Driver for LM3533"
+	depends on BACKLIGHT
+	select DM_I2C
+	help
+	  Say Y to enable the backlight driver for National Semiconductor / TI
+	  LM3533 Lighting Power chip. Only Bank A is supported as for now.
+	  Supported backlight level range is from 2 to 255 with step of 1.
+
 source "drivers/video/ti/Kconfig"
 
 source "drivers/video/exynos/Kconfig"