wcnss: Add support to copy WLAN config file

Copy WLAN config files to data partition at first bootup; this copy is
also done after a factory reset or after an OTA update.  This change
also adds support to plumb certain WCNSS module parameters.

Change-Id: I738e4adec9066b82b499885dbea1801902f78f0b
CRs-Fixed: 516009