wifi: ath12k: add reference counting for core attachment to hardware group

wifi: ath12k: add reference counting for core attachment to hardware group

Currently, driver does not manage reference counting for attaching and
detaching cores to/from hardware groups. This can lead to issues when
multiple cores are involved. Or with same core, attach/detach is called
multiple times back to back.

Fix this issue by using reference counting.

With that, it is now ensured that the core is properly attached or detached
from the hardware group and even back to back calls will not alter the
count.

Additionally, add some debug logs during the attachment and detachment
events for better debugging and tracking.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250408-fix_reboot_issues_with_hw_grouping-v4-2-95e7bf048595@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>