drivers: misc: Generic BLN implementation

Change-Id: Ia515468766b76612e8920c2c73689187048b08e8
serrano: Device implementation of BLN

Change-Id: I8cd70e9915275c4db66c0757a05f1c7b7a43298b
defconfig: serrano: Enable generic BLN

Change-Id: I09d2feeca7bb1200b284a96196c4721e4abd9336
wlan: Get Mac addr from platform driver

Read the MAC address from the platform driver preferrably and
fall back to the option of auto generating the same, if the
MAC read is invalid.

Change-Id: I8a7529bdf7f0d146a2c128a697ebe8c7c374f40a
CRs-Fixed: 583465