iommu/exynos: Pointers are nto physical addresses

The exynos iommu driver changed an incorrect cast from pointer
to 'unsigned int' to an equally incorrect cast to a 'phys_addr_t',
which results in an obvious compile-time error when phys_addr_t
is wider than pointers are:

drivers/iommu/exynos-iommu.c: In function 'alloc_lv2entry':
drivers/iommu/exynos-iommu.c:918:32: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]

The code does not actually want the physical address (which would
involve using virt_to_phys()), but just checks the alignment,
so we can change it to use a cast to uintptr_t instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 740a01ee ("iommu/exynos: Add support for v5 SYSMMU")
Signed-off-by: Joerg Roedel <jroedel@suse.de>