wifi: rtw89: add C2H event handlers of RFK log and report

Trigger a RFK (RF calibration) in firmware by a H2C command, and in
progress it reports log and a result finally by C2H events. Firstly, add
prototype of the C2H event handlers to have a simple picture of framework.

The callers who trigger H2C will wait until a C2H event is received,
so we must process these C2H events in receiving process. Thus, mark this
kind of C2H events as atomic. Also, timestamp is also useful for
debugging, mark C2H events carrying RFK log as atomic as well.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20231213005054.10568-5-pkshih@realtek.com