arm64: ARCH_PFN_OFFSET should be unsigned long

pfns are unsigned long, but PHYS_PFN_OFFSET is phys_addr_t. This leads
to page_to_pfn() returning phys_addr_t which cause type mismatches in
some print statements.
Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/memory.h

@@ -142,7 +142,7 @@ static inline void *phys_to_virt(phys_addr_t x)
  *  virt_to_page(k)	convert a _valid_ virtual address to struct page *
  *  virt_addr_valid(k)	indicates whether a virtual address is valid
  */
-#define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
+#define ARCH_PFN_OFFSET		((unsigned long)PHYS_PFN_OFFSET)
 
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define	virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)