arm64: mm: move dma_contiguous_reserve() to be after paging_init()

[Nick Desaulniers]

It looks like that change referenced may also break arm32 boots with today's
next?

The following allows me to boot, but I have no idea if it's incorrect or not.

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 45f9d5ec2360..7118b98c1f5f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -226,9 +226,6 @@ void __init arm_memblock_init(const struct machine_desc *mdesc)
        early_init_fdt_reserve_self();
        early_init_fdt_scan_reserved_mem();
 
-       /* reserve memory for DMA contiguous allocations */
-       dma_contiguous_reserve(arm_dma_limit);
-
        arm_memblock_steal_permitted = false;
        memblock_dump_all();
 }
@@ -248,6 +245,9 @@ void __init bootmem_init(void)
         */
        sparse_init();
 
+       /* reserve memory for DMA contiguous allocations */
+       dma_contiguous_reserve(arm_dma_limit);
+
        /*
         * Now free the memory - free_area_init needs
         * the sparse mem_map arrays initialized by sparse_init()