wifi: ath10k: Use iommu_paging_domain_alloc()

An iommu domain is allocated in ath10k_fw_init() and is attached to
ar_snoc->fw.dev in the same function. Use iommu_paging_domain_alloc() to
make it explicit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240610085555.88197-11-baolu.lu@linux.intel.com


Signed-off-by: Will Deacon <will@kernel.org>