wl18xx: add time sync configuration api

Add time sync configuration api.
The new api allows to configure the synchronization
mode (STA/AP/MESH) and (in case of Mesh mode) the
master address of each zone.

Signed-off-by: Guy Mishol <guym@ti.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>