ARM: dts: msm: add sync write delay of WLED for QRD8953

Add DT property for sync write delay for WLED module, which is needed
between two consecutive sync register writes, for MSM8953 QRD that
uses PMI8953.

Change-Id: I3d8e5623b9bbedbf6dcd553516cdfff6684de1b7
Signed-off-by: Mao Li <maol@codeaurora.org>