wifi: ath12k: Remove unused declarations

Commit d8899132 ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
declared but never implemented these, remove it.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230816130550.50896-1-yuehaibing@huawei.com