wifi: rtw89: phy: ignore special data from BB parameter file

BB parameter file is a list of tuple {addr, val} with conditional hardware
version. However, tuples within a condition can't be empty, so insert a
special dummy tuple for this case. Then, ignore this tuple when writing.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240105064407.36750-1-pkshih@realtek.com