wiseconnect: Adding firmware update files

Origin: Silicon Labs WiseConnect SDK
License: Zlib
URL: https://github.com/siliconlabs/wiseconnect
Commit: 92d48c57d189b7ceaf622918fb9bc9696dabf2a8
Version: v3.5.2-rc2
Purpose: Integrating firmware upgrade source files to showcase OTA
updates using the Zephyr RTOS.
Using SDK version 3.5.2 instead of 3.5.0 due to missing Zlib
licensing in 3.5.0.Both versions are functionally identical

Signed-off-by: Rahul Gurram <[email protected]>

Author: ragurram26