iommu/mediatek: Fix a build warning of BIT(32) in ARM

The commit ("iommu/mediatek: Enlarge the validate PA range
for 4GB mode") introduce the following build warning while ARCH=arm:

   drivers/iommu/mtk_iommu.c: In function 'mtk_iommu_iova_to_phys':
   include/linux/bitops.h:6:24: warning: left shift count >= width
of type [-Wshift-count-overflow]
    #define BIT(nr)   (1UL << (nr))
                           ^
>> drivers/iommu/mtk_iommu.c:407:9: note: in expansion of macro 'BIT'
      pa |= BIT(32);

  drivers/iommu/mtk_iommu.c: In function 'mtk_iommu_probe':
   include/linux/bitops.h:6:24: warning: left shift count >= width
of type [-Wshift-count-overflow]
    #define BIT(nr)   (1UL << (nr))
                           ^
   drivers/iommu/mtk_iommu.c:589:35: note: in expansion of macro 'BIT'
     data->enable_4GB = !!(max_pfn > (BIT(32) >> PAGE_SHIFT));

Use BIT_ULL instead of BIT.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/mtk_iommu.c

@@ -404,7 +404,7 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,
 	spin_unlock_irqrestore(&dom->pgtlock, flags);
 
 	if (data->enable_4GB)
-		pa |= BIT(32);
+		pa |= BIT_ULL(32);
 
 	return pa;
 }
@@ -586,7 +586,7 @@ static int mtk_iommu_probe(struct platform_device *pdev)
 	data->protect_base = ALIGN(virt_to_phys(protect), MTK_PROTECT_PA_ALIGN);
 
 	/* Whether the current dram is over 4GB */
-	data->enable_4GB = !!(max_pfn > (BIT(32) >> PAGE_SHIFT));
+	data->enable_4GB = !!(max_pfn > (BIT_ULL(32) >> PAGE_SHIFT));
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	data->base = devm_ioremap_resource(dev, res);