iommu/sva: include mmu_notifier.h header

A call to mmu_notifier_arch_invalidate_secondary_tlbs() was introduced in commit e37d5a2d60a3 ("iommu/sva: invalidate stale IOTLB entries for kernel address space") but without explicitly adding its corresponding header file <linux/mmu_notifier.h>. This was evidenced while trying to enable compile testing support for IOMMU_SVA:

config IOMMU_SVA
select IOMMU_MM_DATA
- bool
+ bool "Shared Virtual Addressing" if COMPILE_TEST

The thing is for certain architectures this header file is indirectly included via <asm/tlbflush.h>. However, for others such as 32-bit arm the header is missing and it results in a build failure:

  $ make ARCH=arm allmodconfig
  [...]
  drivers/iommu/iommu-sva.c:340:3: error: call to undeclared function 'mmu_notifier_arch_invalidate_secondary_tlbs' [...]
    340 |  mmu_notifier_arch_invalidate_secondary_tlbs(iommu_mm->mm, start, end);
        |  ^

Fix this by including the appropriate header file.

---
 drivers/iommu/iommu-sva.c | 1 +
 1 file changed, 1 insertion(+)

index d236aef80a8d..e1e63c2be82b 100644
@@ -3,6 +3,7 @@
  * Helpers for IOMMU drivers implementing SVA
  */
 #include <linux/mmu_context.h>
+#include <linux/mmu_notifier.h>
 #include <linux/mutex.h>
 #include <linux/sched/mm.h>
 #include <linux/iommu.h>

2.52.0.358.g0dd7633a29-goog

This patch should be part of a patch-set which does the above. As-is, this does not qualify as a fix or a standalone change.

-Joerg