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
wlan: Use wcnss driver's control interface

Setup the parameters required by wcnss driver thru the control
interface; serial number (for MAC address auto-generation), calibrated
data availability etc. are some of the parameters configured thru this
interface.  These parameters were earlier written thru module parameters,
however that required the wcnss service daemon to have the root permission.

CRs-Fixed: 590457
Change-Id: Ia655ad142c95d542da1ef6b555c13351d6cba5f2
wcnss-service: Preseve old behavior as default

Set TARGET_USES_WCNSS_CTRL := true in Boardconfig to use
the new /dev/wcnss_ctrl and ini in system/etc/wifi

Change-Id: I9912ab03e71c8e0ed4dfd4296e5f12b465ae29d5
wlan: Adding support for batch scan feature

Return the buffer size when driver command is invoked
for batch scan.

Change-Id: I34862f1c97a7747c699f6ada43686523f8b0c6c7
CRs-fixed: 600762