iommu/ipmmu-vmsa: Clean up device tracking

Get rid of now unused device tracking code. Future code should instead
be able to use driver_for_each_device() for this purpose.

This is a simplified version of the following patch from Robin
[PATCH] iommu/ipmmu-vmsa: Clean up group allocation
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/ipmmu-vmsa.c

@@ -37,7 +37,6 @@ struct ipmmu_vmsa_device {
 	struct device *dev;
 	void __iomem *base;
 	struct iommu_device iommu;
-	struct list_head list;
 
 	unsigned int num_utlbs;
 	spinlock_t lock;			/* Protects ctx and domains[] */
@@ -64,9 +63,6 @@ struct ipmmu_vmsa_iommu_priv {
 	struct list_head list;
 };
 
-static DEFINE_SPINLOCK(ipmmu_devices_lock);
-static LIST_HEAD(ipmmu_devices);
-
 static struct ipmmu_vmsa_domain *to_vmsa_domain(struct iommu_domain *dom)
 {
 	return container_of(dom, struct ipmmu_vmsa_domain, io_domain);
@@ -970,10 +966,6 @@ static int ipmmu_probe(struct platform_device *pdev)
 	 * ipmmu_init() after the probe function returns.
 	 */
 
-	spin_lock(&ipmmu_devices_lock);
-	list_add(&mmu->list, &ipmmu_devices);
-	spin_unlock(&ipmmu_devices_lock);
-
 	platform_set_drvdata(pdev, mmu);
 
 	return 0;
@@ -983,10 +975,6 @@ static int ipmmu_remove(struct platform_device *pdev)
 {
 	struct ipmmu_vmsa_device *mmu = platform_get_drvdata(pdev);
 
-	spin_lock(&ipmmu_devices_lock);
-	list_del(&mmu->list);
-	spin_unlock(&ipmmu_devices_lock);
-
 	iommu_device_unregister(&mmu->iommu);
 
 #if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)