iommu/omap: Use the correct type for SLAB_HWCACHE_ALIGN

The macro SLAB_HWCACHE_ALIGN is of type slab_flags_t, but is currently
assigned in the OMAP IOMMU driver using a unsigned long variable. This
generates a sparse warning around the type check. Fix this by defining
the variable flags using the correct type.
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/omap-iommu.c

@@ -1818,7 +1818,7 @@ static const struct iommu_ops omap_iommu_ops = {
 static int __init omap_iommu_init(void)
 {
 	struct kmem_cache *p;
-	const unsigned long flags = SLAB_HWCACHE_ALIGN;
+	const slab_flags_t flags = SLAB_HWCACHE_ALIGN;
 	size_t align = 1 << 10; /* L2 pagetable alignement */
 	struct device_node *np;
 	int ret;