backlight: add driver for Bachmann's ot200

Add backlight driver for Bachmann's ot200 visualisation device.  The
driver uses MFGPT 7 of CS5535 silicon to regulate the backlight.

[akpm@linux-foundation.org: remove redundant test of `brightness']
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Andres Salomon <dilinger@queued.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 49e7d83..248d6c0 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -341,6 +341,13 @@
 	  This supports TI LP8550, LP8551, LP8552, LP8553 and LP8556
 	  backlight driver.
 
+config BACKLIGHT_OT200
+	tristate "Backlight driver for ot200 visualisation device"
+	depends on BACKLIGHT_CLASS_DEVICE && CS5535_MFGPT
+	help
+	  To compile this driver as a module, choose M here: the module will be
+	  called ot200_bl.
+
 endif # BACKLIGHT_CLASS_DEVICE
 
 endif # BACKLIGHT_LCD_SUPPORT