wifi: rtw89: coex: Move coexistence firmware buffer size parameter to chip info

Because RTL8852A/RTL8852C use different firmware buffer size to
send C2H packet, it's necessary to use different size to parse C2H report.

Signed-off-by: Ching-Te Ku <ku920601@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220913092546.43722-4-pkshih@realtek.com