wifi: rtw89: 8922a: declare to support two chanctx

We are going to allow MCC (multi-channel concurrency) on RTL8922A.
So, increase 8922a::support_chanctx_num up to 2 first.

Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240213073514.23796-6-pkshih@realtek.com