wiseconnect: Calendar and RTC SDK files

Origin: Silicon Labs WiseConnect SDK
License: Zlib
URL: https://github.com/siliconlabs/wiseconnect
Commit: 68e44ea22070bb0e594b9974047aed687538aca7
Version: v3.4.0-cf
Purpose: Add Calendar support for SiWx917

Signed-off-by: Martin Hoff <martin.hoff@silabs.com>

Author: Martinhoff-maker