wifi: ath12k: rename the wmi_sc naming convention to wmi_ab

In WMI layer module, the identifier wmi_sc is used to represent
an instance of ath12k_wmi_base structure. However, within ath12k,
the convention is to use "ab" to represent an SoC "base" struct.
So change the all instances of wmi_sc to wmi_ab.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.1.1-00125-QCAHKSWPL_SILICONZ-1

Signed-off-by: Karthikeyan Periyasamy <quic_periyasa@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20231018153008.29820-2-quic_periyasa@quicinc.com