[IA64] remove duplicate include iommu.h

arch/ia64/kernel/pci-dma.c only needs to include iommu once.
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/pci-dma.c

@@ -19,7 +19,6 @@
 #include <linux/kernel.h>
 
 #include <asm/page.h>
-#include <asm/iommu.h>
 
 dma_addr_t bad_dma_address __read_mostly;
 EXPORT_SYMBOL(bad_dma_address);