iommu/s390: Drop duplicate header pci.h

Drop duplicate header pci.h from s390-iommu.c.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/s390-iommu.c

@@ -8,7 +8,6 @@
 #include <linux/pci.h>
 #include <linux/iommu.h>
 #include <linux/iommu-helper.h>
-#include <linux/pci.h>
 #include <linux/sizes.h>
 #include <asm/pci_dma.h>