wifi: rtw89: 8852a: adjust IMR for SER L1

SER (system error recovery) L1 (level 1) has a step-by-step handshake
process with FW. These handshakes still rely on B_AX_HS0ISR_IND_INT_EN.
So, even already during recovery, we enable this bit in IMR.

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://lore.kernel.org/r/20220721074952.19676-1-pkshih@realtek.com