leds: Add new LED driver for lm3642 chips

This driver is a general version for LM642 led chip of TI.

LM3642 :
The LM3642 is a 4MHz fixed-frequency synchronous boost
converter plus 1.5A constant current driver for a high-current
white LED.
The LM3642 is controlled via an I2C-compatible interface.

Signed-off-by: G.Shark Jeong <gshark.jeong@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 0dcb794d..7cfa4d1 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -63,6 +63,17 @@
 	  hardware-accelerated blinking with maximum on and off periods of 9.8
 	  and 77 seconds respectively.
 
+config LEDS_LM3642
+	tristate "LED support for LM3642 Chip"
+	depends on LEDS_CLASS && I2C
+	select REGMAP_I2C
+	help
+	  This option enables support for LEDs connected to LM3642.
+	  The LM3642 is a 4MHz fixed-frequency synchronous boost
+	  converter plus 1.5A constant current driver for a high-current
+	  white LED.
+
+
 config LEDS_LOCOMO
 	tristate "LED Support for Locomo device"
 	depends on LEDS_CLASS