wcnss: update MAC address generate logic from the serial number

The WLAN host driver use device serial number to generate
MAC address. The wcnss platform driver export symbol for
WLAN host driver to read the device serial number to generate
the MAC address. Add updated SOC API to get the device serial
number in the wcnss platform driver.

CRs-Fixed: 2089225
Change-Id: Ic540f2e6e705131f18b59e8f139087d5d99024f6
Signed-off-by: Sarada Prasanna Garnayak <sgarna@codeaurora.org>