rtw89: 8852c: rfk: get calibrated channels to notify firmware

The commit 16b44ed0

 ("rtw89: add RF H2C to notify firmware") is to
add firmware command, and this commit is to prepare the channels. Then,
firmware can get proper channels.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220503120001.79272-2-pkshih@realtek.com