wifi: rtw88: 8822c: extend reserved page number

Extend 8822c's reserved page number to accommodate additional required
pages. Reserved page is an area of memory in the FIFO dedicated for
special purposes. Previously only one interface is supported so 8 pages
should suffice, extend it so we can support 2 interfaces concurrently.

Signed-off-by: Po-Hao Huang <phhuang@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/20230414121135.17828-4-pkshih@realtek.com