Add compatible string to AW2016 led DT node. This was removed from the bulk DT porting for Ravelin on qcom-6.6 device-tree branch. Change-Id: I16d5c93ec542b4ad0adb41a00c569d29fee8b26d Signed-off-by: Shilpa Suresh <quic_c_sbsure@quicinc.com>