flapjack: Enable backlight channel for Flapjackstabilize-11839.Bstabilize-11839.3.B

flapjack requires to enable LED Bias to control LCD backlight.
For C18 boards, three channels are required, and each channel has a
current of 24 mA.
For C19 boards, four channels are required, each channel having a
current of 23.5mA.

BUG=b:124465980
BRANCH=none
TEST=1:)When the system boots, the backlight will light up.
     2:)Use the ectool commands to check the channel and current.
	channle: ectool i2cread 8 0 104 0xA0
	current: ectool i2cread 8 0 104 0xA5
	If it's C18 board, get 0xfa in channel command and 0xc8 in
	current command.
	If it's C19 board, get 0xfe in channel command and 0xc4 in
	current command.
	If the SKU value of the board is empty or incorrect, the default
	value is the data of the C18 board.

Change-Id: I2e51feec830c4cfd46e3eaec0f9db0e1cfdd620c
Reviewed-on: https://chromium-review.googlesource.com/1475094
Commit-Ready: Jessy Jiang <jiangchao5@huaqin.corp-partner.google.com>
Tested-by: Jessy Jiang <jiangchao5@huaqin.corp-partner.google.com>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

0 files changed, 0 insertions, 0 deletions