arm64: Remove dev->archdata.iommu pointer

There are no users left, all drivers have been converted to use the
per-device private pointer offered by IOMMU core.

Signed-off-by: Joerg Roedel <[e-mail]>
Reviewed-by: Jerry Snitselaar <[e-mail]>
Acked-by: Will Deacon <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm64/include/asm/device.h

···
 #define __ASM_DEVICE_H
 
 struct dev_archdata {
-#ifdef CONFIG_IOMMU_API
-	void *iommu;			/* private IOMMU data */
-#endif
 };
 
 struct pdev_archdata {