iommu: Add include/uapi/linux/iommu.h to MAINTAINERS file

When include/uapi/linux/iommu.h was created it was never
added to the file list in MAINTAINERS.

Signed-off-by: Jerry Snitselaar <[email protected]>
Cc: Joerg Roedel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Joerg Roedel <[email protected]>

Author: snits

MAINTAINERS

@@ -9014,6 +9014,7 @@ F:	drivers/iommu/
 F:	include/linux/iommu.h
 F:	include/linux/iova.h
 F:	include/linux/of_iommu.h
+F:	include/uapi/linux/iommu.h
 
 IO_URING
 M:	Jens Axboe <[email protected]>