ARM: S5P64X0: Add PWM backlight support on SMDK6440

This patch adds support for LCD backlight using PWM timer for
Samsung SMDK6440 board.

Signed-off-by: Banajit Goswami <banajit.g@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/mach-s5p64x0/Kconfig b/arch/arm/mach-s5p64x0/Kconfig
index 017af4c..34e2877 100644
--- a/arch/arm/mach-s5p64x0/Kconfig
+++ b/arch/arm/mach-s5p64x0/Kconfig
@@ -36,6 +36,7 @@
 	select S3C_DEV_WDT
 	select S3C64XX_DEV_SPI
 	select SAMSUNG_DEV_ADC
+	select SAMSUNG_DEV_BACKLIGHT
 	select SAMSUNG_DEV_PWM
 	select SAMSUNG_DEV_TS
 	select S5P64X0_SETUP_I2C1