Add version 3.12.1 (released the 2021-02-18) of firmware for Silabs
WF200. This firmware is necessary for the wfx driver currently hosted in
the staging/ directory of the Linux kernel.
Here the last modifications (only modifications tagged [LMAC] have an
impact on Linux):
New Features/Improvements:
[1725] - [UMAC] Wi-Fi power mode API with 'listen_interval = 0' is
taken into account
Bug fixes:
[1710] - [UMAC] Increase WPA3 connection authentication timeout
[1712] - [LMAC] Avoid beacon collision in concurrent mode
[1726] - [LMAC] Fix 'incoherent status and result_flags' warning
[1730] - [UMAC] Fix incorrect packet abort leading to assert
