leds: tlc591xx: Driver for the TI 8/16 Channel i2c LED driver

The TLC59116 is an I2C bus controlled 16-channel LED driver.  The
TLC59108 is an I2C bus controlled 8-channel LED driver, which is very
similar to the TLC59116. Each LED output has its own 8-bit
fixed-frequency PWM controller to control the brightness of the LED.
The LEDs can also be fixed off and on, making them suitable for use as
GPOs.

This is based on a driver from Belkin, but has been extensively
rewritten and extended to support both 08 and 16 versions.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Imre Kaloz <kaloz@openwrt.org>
Cc: Matthew.Fatheree@belkin.com
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>