xen: correctly use xen_pfn_t in remap_domain_mfn_range.

For Xen on ARM a PFN is 64 bits so we need to use the appropriate
type here.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: include the necessary header,
     Reported-by: Fengguang Wu <fengguang.wu@intel.com> ]
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 0f6386a..fd8393f 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2478,7 +2478,7 @@
 
 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 			       unsigned long addr,
-			       unsigned long mfn, int nr,
+			       xen_pfn_t mfn, int nr,
 			       pgprot_t prot, unsigned domid,
 			       struct page **pages)