ARM: dts: msm: add keypad led device tree node for QRD SKUG

SKUG use series leds which fixed in touch panel. We use an
external boost regulator to give power supply, and it's
controlled by GPIO 34. Add device tree node for it.

Change-Id: I176e462258fbc38da20a4a4f9d9d08651e80ebbb
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>