wifi: ath11k: add usecase firmware handling based on device compatible

wifi: ath11k: add usecase firmware handling based on device compatible

For M.2 WLAN chips, there is no suitable DTS node to specify the
firmware-name property. In addition, assigning firmware for the
M.2 PCIe interface causes chips that do not use usecase specific
firmware to fail. Therefore, abandoning the approach of specifying
firmware in DTS. As an alternative, propose a static lookup table
mapping device compatible to firmware names. Currently, only WCN6855
HW2.1 requires this.

However, support for the firmware-name property is retained to keep
the ABI backwards compatible.

For details on usecase specific firmware, see:
https://lore.kernel.org/all/20250522013444.1301330-3-miaoqing.pan@oss.qualcomm.com/.

Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04685-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1

Fixes: edbbc647c4f3 ("wifi: ath11k: support usercase-specific firmware overrides")
Signed-off-by: Miaoqing Pan <miaoqing.pan@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260121095055.3683957-2-miaoqing.pan@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>