rtw88: add deep PS PG mode for 8822c

Compare with LCLK mode, PG mode saves more power, by turning
off more circuits. Therefore, to recover from PG mode, driver
needs to backup some information into rsvd page. Such as CAM
entries, DPK results.

As CAM entries can change, it is required to re-download CAM
entries after set_key.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>